SHIRLEY S. ABRAHAMSON, J.
Each defendant filed a request for substitution of judge in a timely manner and in proper form pursuant to sec. 971.20, Stats. [34]*341979-80. Each circuit court denied the request on the ground that sec. 971.20 is an unconstitutional legislative interference with the functioning of the judicial branch in violation of the Wisconsin Constitution.
Sec. 971.20 permits a defendant to file a statement that “the defendant requests a substitution for the Hon. . . . as judge.” Sec. 971.20(5), Stats. 1979-80. The request for substitution need give no reason for the requested substitution and no grounds for substitution need be proved. When the request for substitution is filed in proper form and in a timely manner, the circuit judge to whom it is addressed loses authority to act in the case.1 Sec. 971.20 creates what is often called [35]*35a peremptory right to substitution, and we shall sometimes refer to sec. 971.20 as a peremptory substitution statute.2
[36]*36The two cases which present the issue of the unconstitutionality of sec. 971.20 have come to this court by different procedural routes. In State v. Holmes, Case No. 81-1669-CR, the defendant, Michael B. Holmes, charged with operating a motor vehicle while under the influence of an intoxicant, filed a request for substitution pursuant to secs. 971.20 and 345.315, Stats. 1979-80.3 The circuit court for Polk county, Robert O. Weisel, circuit judge, against whom the substitution request had been filed, set a hearing upon its own motion for the purpose of considering the constitutionality of the statutes governing substitution of judges.4 By memorandum decision dated August 21, 1980, the circuit court for Polk county declared that all statutes governing substitution of judges “violate the Separation of Powers Doctrine” and denied the defendant’s request for substitution. Both the state and the defendant petitioned the court of appeals for leave to appeal this non-final order. The court of appeals granted the petition for leave to appeal, sec. 808.03(2), Stats. 1979-80, and certified the matter to this court pursuant to sec. 808.05 and sec. (Rule) 809.61, Stats. 1979-80. On October 6, 1981, this court accepted the certification.
In State ex rel. Darian Hudson v. Milwaukee County Circuit Courts, Case No. 81-1774-W, the defendant, [37]*37Darían Hudson, charged with burglary, filed a request for substitution pursuant to sec. 971.20, Stats. 1979-80. The circuit court for Milwaukee county, Ralph Adam Fine, circuit judge, against whom the request had been filed, ordered briefs from the parties on the constitutionality of the statute, upon its own motion. On September 18, 1981, prior to the expiration of the briefing period, the defendant petitioned the court of appeals to exercise supervisory jurisdiction over the circuit court. The defendant sought a writ of prohibition ordering Judge Fine to refrain from taking any further action in the matter. Sec. (Rule) 809.51, Stats. 1979-80. At the same time the defendant petitioned this court to bypass the court of appeals pursuant to sec. 808.05 and sec. (Rule) 809.60, Stats. 1979-80. Defendant’s filing of a petition to bypass stayed the court of appeals from taking under submission defendant’s petition for a supervisory writ. Sec. (Rule) 809.60(3), Stats. 1979-80. On October 6, 1981, this court granted the petition to bypass and agreed to decide defendant’s petition for supervisory writ. The court also granted the state’s motion to intervene. In the interim, by memorandum decision dated September 24, 1981, the circuit court for Milwaukee county declared that sec. 971.20 is “a massive and unwarranted intrusion upon and interference with the circuit court’s constitutionally vested jurisdiction itself. As such it is repugnant to Article VII, sec. 2 [Wis. Const.] .”5
[38]*38For the reasons set forth below, we conclude that the circuit courts have the power to raise sua sponte the issue of the constitutionality of sec. 971.20, Stats. 1979-80, and that the circuit courts in the cases at bar exercised this power in a fair and proper manner. We further conclude that sec. 971.20 was enacted to foster fair trial and that substitution of trial judges to ensure fair trial is an aspect of the judicial system which is subject to reasonable legislative regulation. Any such legislative regulation is, however, subject to the court’s authority to preserve the integrity of the judicial system and to preserve the integrity of the doctrine of separation of powers. Because it has not been proven beyond a reasonable doubt that sec. 971.20 materially impairs or practically defeats the circuit court’s exercise of jurisdiction and power or the proper functioning of the judicial system, we hold that sec. 971.20, Stats. 1979-80, does not violate the doctrine of separation of powers.
I.
Before reaching the issue of the constitutionality of sec. 971.20, we must consider the defendants’ challenge to the circuit courts’ authority to raise the issue of the constitutionality of sec. 971.20 sua sponte.
The defendants’ challenge is predicated on the oft-stated rule that the constitutionality of a statute can be raised only by a party whose rights are directly affected, a party who has a personal stake in the controversy. Wirth v. Ehly, 93 Wis. 2d 433, 448-49, 287 N.W.2d 140 (1980); Mast v. Olsen, 89 Wis. 2d 12, 16, 278 N.W.2d 205 (1979). The defendants contend that because a circuit judge has no personal interest in presiding in a specific case, Berger v. United States, 255 U.S. 22, 35 [39]*39(1921), the judge has no standing to raise the constitutionality of sec. 971.20.
It is true that neither the circuit court nor the circuit judge is a “party” in these cases and therefore neither the circuit court nor the circuit judge has “standing” to pose the constitutional question. But the doctrine of standing is not applicable to the case at bar. The issue in the case at bar is not the circuit court’s “standing” to raise a constitutional issue sua sponte, but rather the proper role of the circuit court during litigation.
There are two apparently inconsistent theories of the proper role of the trial (or appellate) court. One theory is that the litigants control the course of the lawsuit and determine the nature of the questions presented to the courts. The other theory is that the courts have the responsibility to decide cases in accordance with the law and this responsibility is not altered or diminished because counsel fail to identify an issue.6 That the parties, not the courts, should determine the nature of the questions presented is a natural outgrowth of the adversary system and the heavy workload of most courts. The litigants are most familiar with the case, and courts, especially trial courts, do not have the time or staff to do original research in every case to discover issues not raised by the parties. That a court should raise issues sua sponte is the natural outgrowth of the court’s function to do justice between the parties. Although theory and practice militate against a court’s w sponte raising legal issues, it is well recognized that courts may sua [40]*40sponte consider legal issues not raised by the parties. See, e.g., State ex rel. State Bar v. Keller, 16 Wis. 2d 377, 380, 114 N.W.2d 796, 116 N.W.2d 141 (1962).
Courts of course should be reluctant to consider the constitutionality of statutes unless required by the case. Laufenberg v. Cosmetology Examining Board, 87 Wis. 2d 175, 187, 274 N.W.2d 618 (1979). In the instant cases, however, there is adequate justification for the circuit court’s raising the constitutionality of sec. 971.20 sua sponte. This court has said that even where the parties waive the issue, a court “should raise the [constitutional] question itself where it appears necessary to the proper disposition of a case.” State ex rel. Joint School District v. Becker, 194 Wis. 464, 468, 215 N.W. 902 (1928). See also Just v. Marinette County, 56 Wis. 2d 7, 26, 201 N.W.2d 761 (1972). The constitutionality of sec. 971.20 does affect the proper disposition of the case at bar.
Furthermore, because sec. 971.20 affects the circuit court’s role in the judicial system of the state, the circuit courts bringing into question the validity of the statute sua sponte is a valid exercise of what this court has described as the inherent and incidental powers of a circuit court. A circuit court has “inherent power to protect itself against any action that would unreasonably curtail its powers or materially impair its efficiency .... Circuit courts have the incidental power necessary to preserve the full and free exercise of their judicial functions, and to that end may, in appropriate cases, make ex parte orders without formally instituting an action to secure the desired relief.” In Re Court Room, 148 Wis. 109, 121, 134 N.W. 490 (1912). See also, In Re Appointment of Revisor, 141 Wis. 592, 598, 612-13, 124 N.W. 670 (1910).
Any objection to the circuit court’s raising the issue sua sponte on the grounds of the theoretical impropriety [41]*41of the circuit court’s usurping the function of counsel or interfering with the adversary system or of the theoretical unfairness to the litigants is diminished or eliminated by the circuit court’s giving the litigants notice of its consideration of the issue and an opportunity to argue the issue. In the cases at bar, before any decision was rendered, each circuit court posed the question of constitutionality to the parties and gave the parties an opportunity to present legal arguments on the issue. Each circuit court carefully considered the constitutionality of the statute and issued a written memorandum decision which carefully reviewed the legal precedents and which set forth the legal rationale for the decision.
In summary, we conclude that circuit courts have the power to raise and decide the constitutionality of a statute even though the issue was not posed by the parties and that the circuit courts in the instant cases exercised that power in a fair and proper manner. We turn now to the merits of the challenge to the constitutionality of sec. 971.20.
II.
The sole issue on this appeal is whether sec. 971.20, Stats. 1979-80, the substitution of judge statute applicable to criminal cases, violates the state constitution. A presumption of constitutionality attends sec. 971.20 as well as every legislative enactment, and the burden of proving a statute unconstitutional beyond a reasonable .doubt rests upon the party attacking the statute. County of Portage v. Steinpreis, 104 Wis. 2d 466, 478, 312 N.W. 2d 731 (1981).7
[42]*42The circuit courts declared sec. 971.20 unconstitutional as violative of the separation of powers doctrine. Although the principle of separation of powers is not expressly stated in the Wisconsin constitution, it is implicit in the provisions vesting legislative, executive and judicial powers in three separate branches of state government. The pertinent state constitutional provisions are as follows:
“The legislative power shall be vested in a senate and assembly.” Sec. 1, Art. IV, Wis. Const.
“The executive power shall be vested in a governor . . . .” Sec. 1, Art. V, Wis. Const.
“The judicial power of this state shall be vested in a unified court system consisting of one supreme court, a court of appeals, such trial courts of general uniform statewide jurisdiction as the legislature may create by law and a municipal court if authorized by the legislature . . . .” Sec. 2, Art. VII, Wis. Const.
“The supreme court shall have superintending and administrative authority over all courts.” Sec. 3(1), Art. VII, Wis. Const.
“The chief justice of the supreme court shall be the administrative head of the judicial system and shall exercise this administrative authority pursuant to procedures adopted by the supreme court. The chief justice may assign any judge of a court of record to aid in the proper disposition of judicial business in any court of record except the supreme court.” Sec. 4(3), Art. VII, Wis. Const.
The Wisconsin constitution creates three separate coordinate branches of government, no branch subordinate to the other, no branch to arrogate to itself control over the other except as is provided by the constitution, and no branch to exercise the power committed by the constitution to another. This court has recognized, however, that the constitution does not define legislative, executive or judicial power and that it is neither possible nor practicable “to classify accurately all the various gov[43]*43ernmental powers and to say that this power belongs exclusively to one department and that power belongs exclusively to another.” Integration of Bar Case, 244 Wis. 8, 45, 11 N.W.2d 604 (1943). There are “great borderlands of power”8 — “twilight zone[s]”9 — “vast stretches of ambiguous territory”'10 — in which it is difficult to determine where the functions of one branch end and those of another begin. The doctrine of separation of powers does not demand a strict, complete, absolute, scientific division of functions between the three branches of government. The separation of powers doctrine states the principle of shared, rather than completely separated powers. The doctrine envisions a government of separated branches sharing certain powers. State ex rel. Kleczka v. Conta, 82 Wis. 2d 679, 709-711, n. 3, 264 N.W.2d 539 (1978); Layton School of Art & Design v. WERC, 82 Wis. 2d 324, 347-48, 262 N.W.2d 218 (1978); Rules of Court Case, 204 Wis. 501, 503-4, 236 N.W. 717 (1931); In re Appointment of Revisor, 141 Wis. 592, 597, 124 N.W. 670 (1910). For a discussion of the doctrine of separation of powers in Wisconsin, see Currie & Resh, The Separation of Powers — Control of Courts and Lawyers, Dec. 1974 Wis. Bar Bull. 7; Leg. Ref. Bureau, The Powers of the Wisconsin Supreme Court (Res. Bull. 76-RB-1, Jan. 1976). See also Matter of Salary of Juvenile Director, 87 Wash. 2d 232, 552 P.2d 163, 166-172 (1976).
Regulation of substitution of judges falls within the above described vast stretches of ambiguous territory in which the functions of two branches, namely the judicial [44]*44and the legislative, overlap. Both the judiciary and the legislature are empowered to ensure not only that the fairness and integrity of the courts be maintained but also that the operation of the courts be conducted in such a manner as will avoid even the suspicion of unfairness.
It is well established that this court has express, inherent, implied and incidental judicial power. Judicial power extends beyond the power to adjudicate a particular controversy and encompasses the power to regulate matters related to adjudication. The nature of the constitutional grant of judicial power has been described by this court as follows:
“. . . when the people by means of the constitution established courts, they became endowed with all judicial powers essential to carry out the judicial functions delegated to them. ... But the constitution makes no attempt to catalogue the powers granted. . . . These powers are known as incidental, implied, or inherent powers, all of which terms are used to describe those powers which must necessarily be used by the various departments of government in order that they may efficiently perform the functions imposed upon them by the people.” State v. Cannon, 199 Wis. 401, 402, 226 N.W. 385 (1929), quoted with approval in In re Kading, 70 Wis. 2d 508, 517, 235 N.W.2d 409, 238 N.W.2d 63, 239 N.W.2d 297 (1975).
Thus the constitution grants the supreme court power to adopt measures necessary for the due administration of justice in the state, including assuring litigants a fair trial, and to protect the courts and the judicial system against any action that would unreasonably curtail the powers or materially impair the efficacy of the courts or judicial system. Such power, properly used, is essential to the maintenance of a strong and independent judiciary, a necessary component of our system of government. [45]*45In the past, in the exercise of its judicial power this court has regulated the court’s budget, court administration, the bar, and practice and procedure, has appointed counsel at public expense, has created a judicial code of ethics and has disciplined judges.11
[46]*46Although the separation of powers doctrine prohibits the legislature from acting in certain spheres which are exclusively within the power of the courts, the doctrine does not necessarily prohibit the legislature from exercising its legislative public policy making powers in areas that may in some way affect the judicial branch of government. In Integration of Bar Case, 244 Wis. 8, 52, 11 N.W.2d 604 (1948), we stated:
“While the legislature has no constitutional power to compel the court to act or, if it acts, to act in a particular way in the discharge of the judicial function, it may nevertheless with propriety, and in the exercise of its power and the discharge of its duty, declare itself upon questions relating to the general welfare .... The court, as has been exemplified during the entire history of the state will respect such declaration and, as already indicated, adopt them so far as they do not embarrass the court or impair its constitutional functions.”
The legislature, in obedience to its duty to promote the public interest, may enact laws to assure fair trial. Cf. In re Cannon, 206 Wis. 374, 381, 240 N.W. 441 (1932). The legislature may enact statutes which provide the means for assuring litigants their constitutional right to have their cases heard by an unbiased judge, and the legislature may, to effectuate the public policy of maintaining a fair judicial system and public confidence in that system, grant litigants broader rights to challenge a judge than are granted under the constitution so that litigants are assured both the actuality and appearance of a fair trial.12
[47]*47We therefore conclude, as have other state courts which have considered this question, that substitution of trial judges is an aspect of the judicial system which is subject to legislative regulation and that any such legislative regulation is subject to this court’s authority to preserve the integrity of the judicial system and to preserve the integrity of the doctrine of separation of powers. Solberg v. Superior Court, 137 Cal. Rptr. 460, 561 P.2d 1148, 1154 (1977).
Indeed, Wisconsin legislative enactments on the subject of prejudice of a judge can be traced to pre-state-hood years. See Statutes of the Territory of Wisconsin (1839), sec. 10-12, p. 197. See also Laws of Wisconsin (State) 1848, sec. 11, p. 22. Concerned over judicial bias and prejudice and in response to the uncertainty of the common law rules of judicial disqualification,13 many 19th century state legislatures adopted statutes regulating disqualification of judges and substitution of judges.
The first “affidavit of prejudice” procedure in Wisconsin for substituting a judge appears in the context of [48]*48a change of venue statute in the Revised Statutes of 1849,14 and reads as follows:
[49]*49“. . . If either party in any civil cause . . . which may be pending in any court of record in this state, shall fear that he will not receive a fair trial in the county in which such cause is pending, on account that the judge is interested or prejudiced . . . such party may apply to the court in term time, or to any judge in vacation, by petition, setting forth the cause of the application, and praying a change of venue, accompanied by an affidavit verifying the facts of the petition stated; and such court or judge, reasonable notice of the application having been given to the opposite party, or his attorney, shall, if satisfied of the truth of the allegations, award a change of venue to some county where the causes complained of do not exist . . . (Emphasis supplied.) Sec. 1, ch. 95, Rev. Stats. 1849.
The statute was construed in 1853 to require proof of actual prejudice, the truth or falsity of which was to be determined by the judge or court. Hungerford v. Cushing, 2 Wis. 292 (*397), 297-299 (*403-405) (1853). In 1853 the legislature effectively overturned Hunger-ford by amending the 1849 statute to eliminate proof of prejudice or judicial determination of the factual or legal basis of prejudice. The 1853 law provided that where an “affidavit” was made as provided by the 1849 statute, “it shall be the duty of the judge or court to which such application is made to award such change of venue.” Laws of 1853, ch. 51, sec. 1. See also Laws of 1853, ch. 75, sec. 1, extending the affidavit of prejudice to criminal cases.
The 1853 statutory procedure for automatic substitution of a judge on the filing of an affidavit of prejudice remained the law of this state for over 100 years. Immediately prior to the 1969 enactment of sec. 971.20, [50]*50Stats. 1979-80, sec. 956.03, Stats. 1967, governed the substitution of judges in criminal cases and required the filing of an affidavit of prejudice,15 stating that the [51]*51party “has good reason to, and does believe, that he can not have a fair trial on account of the prejudice of the judge.” A simple allegation to that effect, without more, was sufficient to obtain a substitution of judge.16 It was the allegation alone, without proof that prejudice in fact existed, that permitted substitution of the judge, because the allegation imputed prejudice. Bachmann v. City of Milwaukee, 47 Wis. 435, 436, 2 N.W. 543 (1879).
Counsel for the circuit judges concede that the pre-1969 Wisconsin statutes relating to substitution of judges are constitutional enactments. They cite numerous cases from other jurisdictions which have upheld similar affidavit of prejudice statutes as falling within the legislature’s constitutional power to enact reasonable laws to assure fair and impartial trials.17
[52]*52The crux of the challenge to the present statute by counsel for the circuit judges is that the peremptory substitution law is significantly different from the affidavit of prejudice statute and that the arguments validating the affidavit of prejudice statute do not support the validity of the peremptory substitution statute. Counsel for the circuit judges posit two arguments for striking down sec. 971.20, Stats. 1979-80: First, counsel argue that sec. 971.20 is not designed to assure fair and impartial judicial proceedings and therefore the statute does not fall within the general rule upholding substitution statutes as a valid exercise of legislative power to assure fair trial. Second, counsel argue that sec. 971.20 substantially impairs or practically defeats the exercise of the circuit courts’ jurisdiction and power and the proper functioning of the judicial system. We shall consider each argument in turn.
I I — I I — I
Counsel for the circuit judges contend that sec. 971.20 does not, in contrast to its precursors, regulate substitution of trial judges for purposes of assuring litigants a fair trial.18 They assert that the legislative purpose of sec. 971.20 is to give defense attorneys a tactical advantage, i.e., an opportunity to strike a judge for any reason whatsoever. Counsel further argue that this legislative purpose cannot justify legislative interference with the functioning of the court system and accord[53]*53ingly sec. 971.20 violates the doctrine of separation of powers.19
Every state appellate court which has considered a peremptory substitution statute has invalidated the statute,20 reasoning, as do counsel for the circuit judges, that the legislature in allowing the whim, caprice, or uncontrolled power of a lawyer or litigant to determine the power of a judge to hear a case has created an unwarranted and unlawful interference with the constitutional and orderly processes of the courts. Counsel for the circuit judges urge us to adopt the reasoning set forth by the Oregon Supreme Court in distinguishing the [54]*54constitutionality of the affidavit of prejudice statute from the unconstitutionality of peremptory substitution statutes, to-wit:
“[Under the peremptory substitution statute the] legislature has now invested litigants and their attorneys with the power to remove duly appointed or elected and qualified judges from the bench in particular cases at will — for good cause, bad cause, or no cause at all. It may be true that the same thing was possible under the former [affidavit of prejudice] statute, but that was only by an abuse of the statute, not by using it for the purposes which it was manifestly intended to accomplish. Therein lies the distinction between the two laws and the reason why [the affidavit of prejudice statute is constitutional and the peremptory substitution statute is not].” State v. Vandenberg, 203 Or. 326, 280 P.2d 344, 348 (1955). (Emphasis in original.)21
[55]*55We are not persuaded by these decisions because we conclude that they are based on a misconception of the purpose of the peremptory substitution statutes. The legislative objective of sec. 971.20 is the same as that of the earlier affidavit of prejudice statutes, namely, to ensure the right to a fair trial by permitting parties to strike a judge who is prejudiced or gives the appearance of being prejudiced. In sec. 971.20 the legislature merely adopted an alternative procedure to the affidavit of prejudice to accomplish its goal.
While the language of sec. 971.20, unlike that of its precursor affidavit of prejudice statutes, is silent as to bias, prejudice, interest or any other ground as justification for seeking substitution of a judge and is silent as to the objective of assuring a fair trial, the legislative history of sec. 971.20 demonstrates that the enactment was not perceived as changing the purpose or effect of the then-existing affidavit of prejudice statute. The prefatory note by the Judicial Council to ch. 255, Laws of 1969, which created sec. 971.20, makes it clear that the 1969 revision was a change in terminology and pro[56]*56cedure, not a change in substance or in statutory purpose. The Note states as follows:
“While not changing the practical effect of the present affidavit of prejudice law, the bill provides for the ‘substitution of a judge’ upon the written request of the defendant. It is felt that most affidavits of prejudice are not truly that in present practice and it is more realistic to call them by what they really are, a request for another judge to hear the particular case.”
There is however another Judicial Council Note to sec. 971.20, which appears in 42A Wis. Stats. Annot., sec. 971.20, at p. 226 (West 1971), upon which counsel for the circuit judges rely to argue that the purpose of sec. 971.20 is to give defense counsel a tactical advantage, not to assure fair trials. This Judicial Council’s Note to sec. 971.20 comments as follows:
“This [sec. 971.20] is new terminology replacing former s. 956.03(1). ‘Affidavit of Prejudice’ has normally not meant prejudice since most defendants have no knowledge of the judge and have filed the affidavit solely for tactical purposes usually on an attorney’s advice. This terminology is felt to be more accurate.”
Counsel for the circuit judges have, and not without some justification, focused on the use of the phrase “tactical purposes” used by the Judicial Council. The phrase “tactical purposes,” however, must be read in the context of both Notes and in the context of the purpose of and practice under the former affidavit of prejudice statutes.
It is clear from the above-quoted Notes of the Judicial Council and from our prior cases that the affidavit of prejudice statutes had created problems for counsel and the judicial system. Because counsel did not have to set forth the facts giving rise to good reason for the defendant to believe “that he can not have a fair trial on account of the prejudice of the judge” and because no [57]*57court reviewed the sufficiency of the factual premises of the affidavits, no law was developing in this state to guide the lawyers as to the propriety of filing affidavits. In filing the affidavits, lawyers did not know precisely what constituted “prejudice of the judge” under the statute which would justify a belief that the client could not have a “fair trial”. The phrase “prejudice of the judge” in the affidavit of prejudice statute could be interpreted in the traditional narrow sense that the judge had a direct and substantial financial or personal connection with the matter. Or the phrase could be interpreted more broadly to encompass many types of connections the judge may have with the matter that may actually prejudice the judge or may give the appearance that the party may not get a fair and impartial hearing.22
[58]*58When viewed from this historical perspective, the words “tactical purposes” used in the Judicial Council Note do not take on the connotations attributed to them by counsel for the circuit court judges. The words “tactical purposes” allude to the broad interpretation of “prejudice of the judge.” Although the Judicial Council Notes may be inartfully drafted, it is clear that the legislative intent in adopting sec. 971.20 was to give the defendant an opportunity to object to a judge in whose fairness the defendant lacks confidence. Just as the disqualification of a judge perceived to be prejudiced promotes the appearance of a fair trial, the substitution of a judge perceived to be arbitrary, incompetent, irascible, discourteous to counsel, defendant, or witnesses, or unfavorably disposed to the defendant, the attorney or the issues to be tried, may promote the appearance of a fair trial. We conclude, as we did in prior cases, that the objective of the peremptory substitution statute and of the pre-1969 affidavit of prejudice law is the same: to preserve the defendant’s right to a fair trial [59]*59and to ensure the orderly administration of justice. State v. Bell, 62 Wis. 2d 534, 537, 215 N.W.2d 535 (1974); Baldwin v. State, 62 Wis. 2d 521, 532, 215 N.W. 2d 541 (1974). See also State v. Smith, 103 Wis. 2d 361, 363-64, 309 N.W.2d 7 (Ct. App. 1981). The legislature’s elimination of the requirement of an affidavit of prejudice in 1969 is merely a change in the method of accomplishing the legitimate legislative objective of assuring fair trial, not a change of objective.
We acknowledge that sec. 971.20 gives defendants the opportunity to invoke the statute for reasons not related to the goal of preserving fair trial or the appearance of fair trial. Be that as it may, the affidavit of prejudice was also subject to abuse.23 That sec. 971.20 can be abused does not mean that fostering the abuse was the legislative purpose.24
[60]*60The legislative purpose in adopting sec. 971.20 was to remedy the ills caused by the affidavit of prejudice statute. Because the Wisconsin affidavit of prejudice statutes required no substantiation of or determination of the allegation of prejudice, many thought the procedure unjustly impugned the integrity of the judges to whom the affidavits were addressed and that the unchallenged and undetermined charges of judicial prejudice spread on the court records gave the public a distorted picture of judicial impartiality. Some would have preferred, instead of sec. 971.20, that the legislature require the litigant to make a prima facie showing of prejudice and the trial judge (whether the judge to whom the affidavit is addressed or another judge) to rule on the sufficiency of the showing.23 Such a procedure can be viewed as [61]*61too cumbersome, too time consuming and too expensive. In weighing the merits of the alternative approaches to substitution, the legislature obviously concluded that sec. 971.20, which limits the number of substitutions and limits the time for requesting substitution, on balance is a commendable procedure to protect the defendant’s right to a fair trial, to protect the judge from having his or her impartiality unfairly impugned, to avoid having the lawyer file an affidavit of prejudice without having guidelines as to the proper use of the affidavit, and to promote the bench’s and public’s interest in preserving confidence in the judiciary.26
[62]*62While the substitution statute results in potentially productive hours of a judge’s time being expended in travel to hear a case in another county miles away and in higher costs to the state to operate the judicial system, the legislature evidently decided that the inefficiencies, inconveniences and higher costs caused by peremptory substitution are an acceptable price to be paid for the benefits to be derived from peremptory substitution. Nonetheless the legislature must understand that the peremptory substitution statute is another example of a statutorily imposed increased expense in the operation of the judicial system over which the court has no control. These increased costs which are beyond the control of this court take on special import in this era of fiscal economy when this court is asked to decrease the judicial budget and to control expenditures.
While there is continuing dispute about the wisdom of peremptory substitution laws generally, and of the specific terms of sec. 971.20,27 there is also continuing disagreement about the prudence of affidavit of prejudice [63]*63statutes and of the federal system of substitution.28 In any event, peremptory substitution is well recognized as a legitimate means to accomplish the objective of assuring fair trials.
Seven state supreme courts have promulgated rules similar to sec. 971.20.29 Several of these courts have said that the peremptory substitution rule is to protect the right to a fair trial before an impartial judge and that if there are abuses by counsel in peremptory sub[64]*64stitutions, the abuses should be corrected by amendments to the rule, not by abandoning the concept of peremptory substitution. The Montana Supreme Court summarized this view as follows:
“The purpose of the rule is to guarantee both the prosecution and the defendant a fair trial before an impartial district judge ....
“We recognize that the right of peremptory disqualification of district judges creates delays in the trial of both criminal and civil cases in Montana. It causes calendaring and scheduling problems for district judges, the parties and their attorneys. It interferes with the normal and routine operation of the district courts. Nonetheless we hold that the paramount and overriding consideration is the right to a fair trial before any impartial district judge. We consider that improvements in the present system lie in the area of correction of abuses in the exercise of peremptory disqualifications rather than elimination of the right.” State ex rel. Greely v. Dist. Ct. of 4th Jud. Dist., 590 P.2d 1104, 1108 (Mont. 1979).
Our conclusion that the Wisconsin peremptory substitution statute is a well-recognized means to ensure a fair trial is corroborated by the recommendations of the National Conference of the Commissioners on Uniform State Laws and the American Bar Association Commission on Standards of Judicial Administration. Rule 741 (a) of the Uniform Rules of Criminal Procedure, 10 Uniform Laws Annotated Rule 741, pp. 854-357 (1974), allows a defendant to obtain substitution of a judge upon timely demand.30
[65]*65Although ABA Standard 2.32 in Standards Relating to Trial Courts (1976) provides for disqualification of a judge upon motion to disqualify for cause, with the judge against whom a motion was filed determining whether the motion was legally sufficient on its face and with another judge resolving factual issues raised by the motion,31 the Commission recommended that considera[66]*66tion be given to adopting a peremptory substitution procedure similar to sec. 971.20. The Commission explained that the theory of peremptory substitution is that a party should be able to refrain from having his case heard by a judge who, though not disqualified for cause on the grounds set forth in the ABA Code of Judicial Conduct, the party believes will not grant him a fair trial. The Commission went on to explain that it viewed the concept of peremptory substitution as one recognized by implication in the “affidavit of prejudice” laws which, according to the Commission, evidence a deeply felt need for enlarging the basis upon which a party may object to a judge. The peremptory substitution is a formal recognition of this deeply felt need to allow a party to avoid, in a manner consonant with the sound administration of a court’s work, a judge in whose fairness or understanding the party lacks confidence and thus to provide additional assurance to the parties that their case will be determined justly. The Commission urged adoption of peremptory substitution commenting as follows:
“. . . Consideration should be given to adopting a procedure for peremptory challenge of a judge. The theory of such a procedure is that a party should be able to avoid having his case tried by a judge who, though he is not disqualified for cause, the party believes cannot afford him a fair trial. Such a belief may stem from the judge’s views or practices regarding the type of case in question, from the judge’s inexperience with the type of matter involved, or from previous interchanges between the judge and the party or his counsel. One or more of these considerations may weigh heavily where the disposition of the matter involves a broad range of un-reviewable discretion on the part of the judge or where the trial of a matter is likely to be long or complicated. Although a party is not entitled to have his case heard by a judge of his selection, he should not be compelled to accept a judge in whose fairness or understanding he [67]*67lacks confidence if that can be avoided without interfering with administration of the court’s work.
“The concept of peremptory challenge of a judge, similar to that established with respect to jurors, is recognized by implication in jurisdictions where a challenge based on cause is given effect without requiring substantiation of its allegations. This practice unjustifiably impugns the integrity of the judge to whom such a challenge is addressed and perverts the procedure of recusal for cause. Nevertheless, it evidences a deeply felt need for enlarging the basis upon which a party may object to a judge. If the procedure for peremptory challenge of a judge is formally recognized as such, it can provide an additional measure of assurance to the parties that their case will be justly determined. Experience in jurisdictions having the peremptory challenge procedure indicates that, when subject to proper controls and limitations it can provide this assurance without burdensome additional cost or complications in trial court administration.
“A procedure for peremptory challenge of a judge should have provisions for prompt assignment of another judge to replace one who has been challenged. Such provisions are of especial importance where a challenge has been made in a matter requiring immediate judicial action, such as an application for a temporary injunction. In judicial districts having only one or two judges, adoption of the peremptory challenge procedures may be impractical unless there are also administrative arrangements whereby a replacement judge can be assigned from elsewhere.” Sec. 2.32, Commentary, pp. 51-53.
We acknowledge that sec. 971.20 can be abused and can result in litigants and lawyers delaying judicial proceedings and arbitrarily interfering with judicial proceedings. As discussed more fully later, the sincerity of the circuit judges’ concern that sec. 971.20 will be used by the bar to isolate a particular judge and to interfere with the independence of the judiciary is not questioned. That the wisdom of sec. 971.20 is being seriously chai-[68]*68lenged and that there is dissatisfaction with the operation of sec. 971.20 is clear from the number of bills presented to the legislature to modify sec. 971.20. Although the legislature may on reconsideration decide that sec. 971.20 or some of its terms do not represent the best balance of the defendant’s right to a fair trial and the efficient operation of the judicial system, this court cannot conclude that sec. 971.20 is an unconstitutional exercise of legislative power to ensure fair trials.
IV.
Although the legislature is not prohibited by the doctrine of separation of powers from enacting reasonable laws regulating substitution of judges to assure a fair trial and the appearance of a fair trial, the doctrine of separation of powers does impose significant limitations on the legislature’s exercise of its power. Under the doctrine of separation of powers, the legislature is prohibited from unduly burdening or substantially interfering with the judicial branch.32
In addition, we are cognizant that the constitution mandates that this court have “superintending and administrative authority over all courts,” sec. 3(1) and sec. 4(3), Art. VII, Wis. Const., and that legislative enactments which do not unduly burden or substantially interfere with the judicial branch may nevertheless unconstitutionally interfere with this court’s superintending and administrative authority.
In Integration of Bar Case, 244 Wis. 8, 49, 11 N.W.2d 604, 12 N.W.2d 699 (1943), this court spelled out the [69]*69circumstances under which legislative regulation constitutes an unconstitutional infringement on the judiciary as follows: When “the exercise of administrative and legislative power ha[s] so far invaded the judicial field as to embarrass the court and impair its proper functioning,” the court will be “compelled to maintain its integrity as a constitutional institution.”
Using slightly different language, in John F. Jelke Co. v. Beck, 208 Wis. 650, 660, 242 N.W. 576 (1932), this court set forth the limitation on the legislative power as follows:
“In Wisconsin jurisdiction and power of the court is conferred not by act of the legislature but by the constitution itself. While the legislature may regulate in the 'public interest the exercise of the judicial power, it cannot, under the guise of regulation, withdraw that power or so limit and circumscribe it as to defeat the constitutional purpose.”
Accordingly the question becomes whether the operation of sec. 971.20, including defendants’ possible abuse of the right of substitution for purposes unrelated to securing a fair trial, materially impairs or practically defeats the circuit court’s exercise of jurisdiction and power or the proper functioning of the judicial system so as to constitute a violation of the doctrine of separation of powers. The state contends, and we agree, that there has been no showing, beyond a reasonable doubt, that sec. 971.20, Stats., so affects the operation of the judicial system.
There is no showing that the peremptory substitution .statute defeats the circuit courts’ exercise of judicial power. Sec. 971.20 leaves intact the circuit court’s judicial power to deal with the case, although the substitution request does stop a particular circuit judge from exercising his or her authority to hear the particular [70]*70case. As the California Supreme Court said regarding California’s affidavit of prejudice statute:
“. . . The effect of the statute here challenged is at most to remove the individual judge assigned to the case or the department, but not to deprive the court of the power to hear such cases by assignment of another judge.” Solberg v. Superior Court, 561 P.2d at 1161 n. 22 (emphasis in original).
See also U’ren v. Bagley, 118 Or. 77, 245 P. 1074, 1076 (1926).
Although the test “material impairment or practical defeat of the proper functioning of the judicial system” is not without ambiguity, we conclude that it has not been proven beyond a reasonable doubt that the peremptory substitution statute materially impairs or practically defeats the proper functioning of the judicial system. The state asks this court to take judicial notice of figures supplied by the Office of the Director of State Courts estimating the number of requests for substitution filed in 1981. See sec. 902.01(2), Stats. 1979-80, and sec. 902.01(4), Stats. 1979-80. While statistics do not tell the whole story, they may cast some light on the impact the substitution of judge statute has on the judicial system in Wisconsin. The Office of the Director of State Courts reports that between January 1, 1981 and March 31, 1981, approximately 71,400 cases were filed, 11,112 criminal and 60,288 civil, and that 1224 substitution requests were filed, 496 in criminal matters, and 728 in civil matters. On the basis of these figures for the first quarter, we estimate that about 4,900 substitution requests were filed in 1981 in a total of 286,000 case filings. Thus substitution requests were probably filed in 1981 in less than 2 percent of the cases overall and in less than 5 percent of the criminal cases. When viewed from the perspective of the number of judges who must be replaced, the statistics indicate that substitutions may [71]*71have an impact on the operation of the judicial system. Considered in terms of percentages of total cases, the substitution requests do not seem to play a role in the operation of the judicial system of this state. Whether the requests for substitution have a significant impact or play a significant role is not known and whether they materially impair the operation of the judicial system has not been proved. These statistics do not provide quantitative evidence from which we can conclude that substitution requests materially impair or practically defeat the ability of the judicial system to dispose of the cases presented.
Nevertheless the circuit courts determined that sec. 971.20 has adverse effects on the administration of justice which, beyond a reasonable doubt, justify holding the statute unconstitutional.
The circuit courts decided that peremptory substitution of judges causes delay in the disposition of cases. See Holmes memorandum decision at 9; Hudson memorandum decision at 18. Although there are no hard statistical data on delay, common sense tells us that a. request for substitution is likely to cause delay in the disposition of the case and that the chances for delay are greater in single-judge circuits than in multi-judge circuits. The circuit judges of this state who deal with substitution requests on a daily basis perceive substitution requests to be a major source of delay in our court system. See Resource Planning Corporation for the State of Wisconsin Judicial Planning Committee, Wisconsin Case Processing Study Final Report (July 1, 1978), p. 478, discussed in Justice Coffey’s concurring opinion in State ex rel. Tarney v. McCormack, 99 Wis. 2d 220, 238 n. 2, 298 N.W.2d 552 (1980).
We note that the legislature has attempted to keep delay to the minimum to assure “the efficient adminis[72]*72tration of court calendaring” by circumscribing the time within which a request for a substitution of the judge may be made. State v. Bell, 62 Wis. 2d 534, 537, 215 N.W.2d 535 (1974). See also State v. Smith, 103 Wis. 2d 361, 364, 309 N.W.2d 7 (Ct. App. 1981). Whether the costs of delay outweigh, or are outweighed by, the beneficial aspects of the statute is not before us in these cases. The legislature’s balancing of these factors will be accepted unless the statute practically defeats the exercise of the judicial power or materially impairs the operation of the judicial system. On the basis of the record before us we cannot find beyond a reasonable doubt that the delay caused by the peremptory substitution of judges is so great as to materially impair or practically defeat the criminal justice system.
The circuit courts found that peremptory substitution produces inefficiencies and inconveniences and increases the state’s costs in the disposition of.cases. See Holmes memorandum decision at 9; Hudson memorandum decision at 13-14.
Again, common sense tells us that a peremptory substitution law does cause inefficiencies, inconveniences and increased expenses and that these effects will be greater in single-judge circuits than in multi-judge circuits. Nevertheless, those cases in which substitution requests have been filed are being heard and disposed of, even though perhaps in some cases not as efficiently or conveniently or at minimum cost as they might be were there a more restrictive substitution procedure.
Finally, the circuit courts concluded that peremptory substitution of judges allows a litigant to remove a judge whom he or she perceives as handling and disposing of cases in a manner unfavorable to the interests of the litigant and that such abuse of the right to a fair trial permits judge shopping (Holmes memorandum decision [73]*73at 9, Hudson memorandum decision at 18) ,33 provides criminal defendants with “a mechanism for avoiding judges perceived as tough sentencers” (Hudson memorandum decision at 16), gives the bar “power to control the Court” (Holmes memorandum decision at 8), and undermines innovative attempts at discipline and reform of the judicial system (Holmes memorandum decision at 8).
These criticisms of the peremptory substitution statute cannot be measured by figures and statistics. These criticisms reflect the subtle effects of sec. 971.20: the disruption of the orderly conduct of judicial business, the demoralization of court dockets, and the threat to judicial independence. Judge Weisel in his memorandum decision in Holmes eloquently expressed these concerns as follows:
“None of the decisions cited [from other jurisdictions invalidating peremptory substitution statutes] have touched upon the subtle and unconscious effect that these statutes have upon the trial judge. Perhaps it is because they were written by appellate judges. Under these statutes a judge lives knowing, perhaps not caring, that at any time the Bar can exercise its potential power and literally force out that judge of ever trying another case in the county in which he has been elected as circuit judge. Like it or not, deny it if you will, the Bar under these statutes has that power. ... No judge will admit to being influenced by it. No judge honest with himself will deny that he is not bothered by it.
“Should we, as an independent judiciary, have to live under that cloud ? There is a subtle threat to conform to the Bar’s standards of practice. The judge who deviates from that norm set by the local Bar is faced with re[74]*74peated requests for substitution. He is then under a subtle force, or at least incurs the displeasure of the Court Administrator’s office and from the Bar. We are exposed to this power every day. It cannot help but have a stifling- effect upon the innovation of court procedures, and attempts by the court to solve the problem. The result is the loss of the independence of the judiciary. It stifles the court’s attempts at discipline, at reform, at efficiency which is met not by cooperation from the local Bar which has traditionally resisted change, but by antagonism and the subsequent requests for substitution of judge. The judge is faced with situations where he cannot fulfill his oath of office because he is prevented from doing so by the whim and caprice of counsel.” Memorandum Decision at 8.
This court is not unmindful of the concerns expressed by Judge Weisel. On two recent occasions members of this court have expressed concern over the potential abuse of sec. 971.20 and have urged the legislature to correct the defects in the statute. See State ex rel. Warrington v. Circuit Court for Shawano County, 100 Wis. 2d 726, 738-89, 303 N.W.2d 590 (1981) (Justice Callow concurring); State ex rel. Tarney v. McCormack, 99 Wis. 2d 220, 236-40, 298 N.W.2d 552 (1980) (Justice Coffey concurring). And there is reason to believe that the legislature is sensitive to the inefficiencies and difficulties which exist in the operation of the existing substitution statutes and is ready and willing to modify sec. 971.20 to remove such undesirable features as it can consistent with its goal of securing both the fact of and appearance of fairness in judicial proceedings.
Regardless of each individual justice’s view of the wisdom of sec. 971.20, and we are not all of one mind, we are unanimous in concluding that the statute does not violate the constitutional doctrine of separation of powers. We therefore reverse the order of the circuit court for Polk county. We order that a writ of prohibition issue directing the circuit court for Milwaukee county, [75]*75Ralph Adam Fine, circuit judge, to refrain from taking any further action in the above-captioned matter. And we remand the causes to the respective circuit courts for further proceedings not inconsistent with this opinion.
By the Court. — The order of the circuit court for Polk county is reversed; a writ of prohibition is issued directing the circuit court for Milwaukee county, Ralph Adam Fine, circuit judge, to refrain from taking any further action in the above-captioned matter; and the causes are remanded to the respective circuit courts for proceedings not inconsistent with this opinion.