RUSSON, Justice:
Mason A. Ohms appeals his conviction of giving false or misleading information to a police officer, a class C misdemeanor, in violation of Salt Lake City Ordinance § 11.04.-100. We reverse and remand.
I. FACTS
At approximately 9:30 p.m. on August 25, 1992, a disturbance involving the distribution of beer erupted in the third-level plaza area of the Delta Center. Sergeant Foster Mayo of the Salt Lake City Police Department, who was working security duty at the Delta Center, intervened and placed Mason A. Ohms under arrest for battery, a class B misdemeanor, in violation of Salt Lake City Ordinance § 11.08.020. After taking Ohms to a holding room, Sergeant Mayo asked him for identification, at which time Ohms produced a driver’s license bearing the name Scott Smith. Sergeant Mayo asked Ohms if this was his driver’s license and if he was Smith; Ohms answered both questions in the affirmative.
After Sergeant Mayo and other officers began the requisite paperwork using the Smith identification, one officer noticed that Ohms did not match the physical description on the driver’s license. When confronted with the discrepancy, Ohms produced a second driver’s license bearing his correct name. Ohms was subsequently charged with providing false or misleading information to a police officer, a class C misdemeanor.
Prior to his trial on both misdemeanor charges, Ohms signed a waiver and consent form in which he (1) acknowledged his right to a trial before a third circuit court judge with or without a jury, (2) waived that right, and (3) consented to have his case tried and final judgment entered by a circuit court commissioner.1 Following a trial before Third Circuit Court Commissioner Sandra N. Peuler on December 15, 1992, Ohms was convicted by her of providing false or misleading information to a police officer and sentenced to three days in the Salt Lake County Jail, which sentence was suspended upon payment of a $100 fine.2
Ohms appealed his conviction to the Utah Court of Appeals, which certified his appeal to this court, pursuant to Utah Rule of Appellate Procedure 43(a).3 On certification, Ohms challenges (1) the circuit court commissioner’s authority to enter final judgment, and (2) the sufficiency of the evidence supporting his conviction. Salt Lake City responds that (1) Ohms, having never challenged the authority of the court commissioner below, may not raise this argument for the first time on appeal; and (2) the evidence is sufficient to support Ohms’ conviction.4
II. AUTHORITY OF COURT COMMISSIONERS
On certification, Ohms argues that the circuit court commissioner lacked authority to enter final judgment in his case. Specifically, he asserts that Utah Code Ann. § 78-3-31 (1992) is unconstitutional insofar as it delegates ultimate judicial power to court commissioners in violation of article VIII of the Utah Constitution. Ohms bases his argument on Holm v. Smilowitz, 840 P.2d 157 [847]*847(Utah Ct.App.1992). However, while addressing similar concerns, Holm is distinguishable from the present case because it addresses only the authority of court commissioners to hear nonconsent civil cases.5 The matter before us now is a crinjinal case involving consent.
Salt Lake City responds that since Ohms did not challenge the authority of the court commissioner or raise the constitutionality of section 78-3-31 below, he may not now raise these arguments for the first time on appeal. Alternatively, Salt Lake City contends that since Ohms (1) knowingly and voluntarily waived his right to have his case tried and final judgment entered by a third circuit court judge with or without a jury and (2) consented to have his case tried and final judgment entered by a court commissioner, he cannot now, having received an unfavorable verdict, challenge the validity of that waiver and consent.
As a general rule, we will review issues raised for the first time on appeal only if exceptional circumstances or “plain error” exists. See, e.g., State v. Brown, 853 P.2d 851, 853-54 (Utah 1992); State v. Gibbons, 740 P.2d 1309, 1311 (Utah 1987); State v. Steggell, 660 P.2d 252, 254 (Utah 1983). In the present case, or in any similar case, the only way that a defendant could challenge the constitutionality of section 78 — 3—31(6)(a) would be first to consent to a hearing by a commissioner and then to challenge the validity of that very consent. Such a procedure would likely be futile inasmuch as it would invariably result in the withdrawal of the consent, either by the defendant or by court order. Indeed, absent the approach taken by Ohms, it is unlikely that section 78-3-31(6)(a) would ever be subject to constitutional scrutiny. This is precisely the sort of exceptional circumstance that permits us to review the constitutionality of the provision in question. Accordingly, even though Ohms did not challenge the constitutionality of seetion 78-3-31 below, we nonetheless address this argument on appeal.
Our analysis of the constitutionality of section 78-3-31 begins with the premise that “statutes are presumed to be constitutional.” State v. Rio Vista Oil, Ltd., 786 P.2d 1343, 1349 (Utah 1990). As this court stated in In re Estate of Baer:
The decisions of this court unanimously support a presumption of constitutionality of legislative enactments. In determining constitutionality, statutes are presumed to be constitutional until the contrary is clearly shown. It is only when statutes manifestly infringe upon some constitutional provision that they can be declared void. Every reasonable presumption must be indulged in and every reasonable doubt resolved in favor of constitutionality.
In re Estate of Baer, 562 P.2d 614, 616 (Utah), appeal dismissed sub nom. Baer v. Baer, 434 U.S. 805, 98 S.Ct. 35, 54 L.Ed.2d 63 (1977); see also Murray City v. Hall, 663 P.2d 1314, 1317-18 (Utah 1983) (holding that statutes “‘are endowed "with a strong presumption of validity; and that they should not be declared unconstitutional if there is any reasonable basis upon which they can be found to come within the constitutional frame work [sic]’” (quoting Greaves v. State, 528 P.2d 805, 807 (Utah 1974))). Nonetheless, when a proper challenge to the constitutionality of a given statute is made, the said statute must be examined to determine if it is unconstitutional, either on its face or as applied. See, e.g., In re Criminal Investigation, 7th Dist. Court No. CS-1, 754 P.2d 633, 640 (Utah 1988); Wells v. Children’s Aid Soc’y of Utah, 681 P.2d 199, 204 (Utah 1984); Ellis v. Social Servs. Dep’t of Church of Jesus Christ of Latter-day Saints, 615 P.2d 1250, 1255 (Utah 1980).
The statute at issue in this ease provides in part:
[848]*848Court commissioners are quasi-judicial officers of courts of record and have judicial authority as provided by this section and rules of the Judicial Council.6
It further states:
Upon the informed consent of the defendant, the court commissioner may conduct a jury or nonjury misdemeanor trial in accordance with the law. Upon conviction, the commissioner may impose sentence and enter final judgment. The judgment entered by the commissioner shall be the final judgment of the court for all purposes, including appeal.7
Article VIII, section 1 of the Utah Constitution, much like article III, section 1 of the United States Constitution, provides that the judicial power of the state shall be vested in the courts. However, unlike its federal counterpart, the Utah Constitution further delineates certain requirements concerning the selection and retention of those who will exercise that judicial power. See Utah Const, art. VIII, §§ 8, 9, & 13. Thus, under state law, examination of the constitutionality of section 78-3-31 consists of two inquiries: (1) whether section 78-3-31 violates the Utah Constitution’s exclusive vesting of the state’s judicial power in article VIII courts,8 and (2) whether section 78-3-31 violates the Utah Constitution’s requirements for those persons exercising that judicial power in courts of record.9
A Constitutional Powers of Article VIII Courts
Core functions or powers of the various branches of government are clearly nondelegable under the Utah Constitution. See, e.g., Sandy City v. Salt Lake County, 827 P.2d 212, 221 (Utah 1992) (holding that legislative functions, such as powers of zoning and rezoning, cannot be delegated); State v. Gallion, 572 P.2d 683, 687 (Utah 1977) (holding that Utah Const, art. VI, § 1 limits legislature’s ability to delegate legislative powers or functions to others); In re Bridwell, 25 Utah 2d 1, 2, 474 P.2d 116, 116 (Utah 1970) (holding that Utah Supreme Court cannot delegate its duty to discipline an erring attorney to others); accord State v. Green, 793 P.2d 912, 916 (Utah Ct.App.1990) (holding that “crime definition and penalty powers are essential legislative functions that cannot constitutionally be delegated by the Utah Legislature to any other person or body”). For example, a legislator cannot appoint another person to cast his or her vote on the floor of the legislature. Although a legislator can utilize assistants for various purposes, these assistants cannot exercise the legislator’s voting power since such is a core legislative function. It is the legislator, not his or her staff, who is elected for that purpose, and it is the legislator who is accountable to the people.
Likewise, a judge cannot appoint another person to enter final judgments and orders or impose sentence. While he or she can utilize referees, court commissioners, and other assistants for various purposes, those persons cannot exercise that judge’s ultimate judicial power, for such is a nondelegable core judicial function. In courts of record, it is the judge who is selected by a precise constitutional procedure to exercise judicial power, and it is the judge, not other “quasi-judicial” officers, who is subject to the ac[849]*849countability provisions of the Utah Constitution.
Based on these principles, our present inquiry focuses on whether the authority delegated to the commissioner here involves core judicial power of a court of record.10 “The term ‘judicial power of courts’ is generally understood to be the power to hear and determine controversies between adverse parties and questions in litigation.” Timpanogos Planning & Water Management Agency v. Central Utah Water Conservancy Dist., 690 P.2d 562, 569 (Utah 1984) (quoting Citizens’ Club v. Welling, 88 Utah 81, 90, 27 P.2d 23, 26 (1933)). Such core judicial powers include ‘“the authority to hear and determine justiciable controversies’ ” as well as “ ‘the authority to enforce any valid judgment, decree or order.’ ” Id. (quoting Galloway v. Truesdell, 83 Nev. 13, 422 P.2d 237, 242 (1967)). Further, core judicial functions necessarily include all powers that are “necessary to protect the fundamental integrity of the judicial branch” and, as such, may not be delegated to persons other than judicial officers. Criminal Investigation, 754 P.2d at 642.
Article VIII, section 1 of the Utah Constitution states:
The judicial power of the state shall be vested in a supreme court, in a trial court of general jurisdiction known as the district court, and in such other courts as the Legislature by statute may establish. The Supreme Court, the district court, and such other courts designated by statute shall be courts of record. Courts not of record shall also be established by statute.
Thus, article VIII, section 1 specifically creates a supreme court and district courts as courts of record and gives the legislature the power to create other courts, including additional courts of record, by statute. The legislature has created circuit courts, as well as the court of appeals and juvenile courts, as additional courts of record.11 The Utah Constitution also establishes the jurisdiction of the various state courts of record: article VIII, section 1 provides that district courts have general jurisdiction; article VIII, section 3 sets forth the jurisdiction of the supreme court, and article VIII, section 5 states that the jurisdiction of courts of record established by the legislature shall be provided by statute.12 Moreover, article VUI’s explicit vesting of jurisdiction in the various courts of the state is an implicit prohibition against any attempt to vest such jurisdiction elsewhere.
B. Constitutional Requirements for Exercise of Judicial Power
The Utah Constitution specifically provides that individuals who exercise the judicial power of the state in courts of record must be selected “solely upon consideration of fitness for office without regard to any partisan political consideration,” Utah Const. [850]*850art. VIII, § 8, and further dictates how those individuals are chosen.
Article VIII, section 8 provides that judicial appointments to courts of record are made by the governor from a list of names submitted by a judicial nominating commission,13 which appointment must then be approved by the state senate. Only upon completion of this process can the selected individual assume the office of judge of a court of record. Even then, that judge must submit to a retention election by the electorate after serving in office for three years, and on a regular basis thereafter. Utah Const, art. VIII, § 9. Furthermore, that judge is subject to review by a judicial conduct commission, which has the power to investigate complaints and recommend sanctions where appropriate. Utah Const, art. VIII, § 13. Thus, throughout their tenure, article VIII judges of courts of record remain accountable for their actions.14
In short, those persons who exercise judicial power in courts of record are subject to both careful selection and continuing review as set forth in the Utah Constitution. Any attempt by either the legislature or the judicial council to transfer or assign the power of such judges to others would plainly circumvent and violate the Utah Constitution. It would deprive the judicial nominating commission of its constitutional right to select and submit judicial nominees to the governor, it would deprive the governor' of the constitutional right to choose judges of courts of record, and it would deprive the people of the state of Utah of their constitutional right to vote on judges of courts of record in retention elections.
C. Section 78-3-31
Returning to the statute at issue, Utah Code Ann. § 78-3-81 (1992) provides for the appointment of court commissioners to exercise the judicial authority of courts of record without subjecting them to the selection and retention requirements mandated by the Utah Constitution. Specifically, that statute states:
Court commissioners are quasi-judicial officers of courts of record and have judicial authority as provided by this section and rules of the Judicial Council.15
The statute further provides:
Upon the informed consent of the defendant, the court commissioner may conduct a jury or nonjury misdemeanor trial in accordance with the law. Upon conviction, the commissioner may impose sentence and enter final judgment. The judgment entered by the commissioner shall be the [851]*851final judgment of the court for all purposes, including appeal.16
Insofar as these sections purport to grant ultimate judicial power and authority to court commissioners in courts of record, such as the power to enter judgment and impose sentence in the case at bar, they violate article VIII of the Utah Constitution. This is true for the following reasons.
1. Article VIII, Section 8
Permitting court commissioners to perform core judicial functions, as section 78-3-31(l)(a) and (6)(a) purports to do, violates article VIII, section 8’s provision that all article VIII judges of courts of record must be certified by a judicial nominating commission to the governor, who then makes the appointment with the approval of the state senate. While court commissioners, as “quasi-judicial officers,” Utah Code Ann. § 78-3-31(l)(a) (1992), may perform many important functions in assistance to courts of record,17 they are not duly appointed judges and thus may not exercise core judicial functions without violating article VIII of the Utah Constitution. Court commissioners are employees of the judiciary, not duly appointed judges. There are no provisions which subject them to the constitutional checks and balances imposed upon duly appointed judges of courts of record. Similarly, while court commissioners are, under present statutory law, [852]*852subject to continuing review by a judicial conduct commission, see Utah Code Ann. § 78-3-31(8)(b) (1992), they are not constitutionally subject to such review, nor are they subject to judicial retention elections that do apply to judges of courts of record. Utah Const, art. VIII, §§ 9 & 13.18
2. Separation of Powers
Permitting the legislature to grant court commissioners authority to enter final judgment and impose sentence violates the separation of powers doctrine. The dissent argues that since, under the court commissioner system, the judicial power is being delegated to persons entirely within the control of the judiciary, there is no separation of powers problem. However, their argument misses the point. By granting commissioners “judicial authority as provided by this section," Utah Code Ann. § 78-3-31(l)(a) (1992) (emphasis added), the legislature has assumed the right to vest commissioners with judicial power and define the bounds of commissioner authority. The very attempt by the legislature to designate an individual other than a duly appointed judge to wield ultimate judicial power is, in and of itself, a violation of the separation of powers doctrine. Oversight of that individual by the judiciary is irrelevant because of the constitutional requirement that only duly appointed judges exercise ultimate judicial power in courts of record.19
3. Subject Matter Jurisdiction
Subject matter jurisdiction is “the authority and competency of the court to decide the case.” Department of Social Servs. v. Vijil, [853]*853784 P.2d 1130, 1132 (Utah 1989) (emphasis added) (citing 5 Charles A. Wright & Arthur R. Miller, Federal Practice and Procedure § 1350 (1969)). The jurisdiction of circuit courts is set forth in Utah Code Ann. §§ 78-4 — 5 and -7 (1992 & Supp.1993) and clearly includes the power and authority to decide the matter at issue in the present case. Thus, the third circuit court had jurisdiction in this case.
However, that does not resolve the question of whether the individual exercising that court’s jurisdiction had the authority to do so. Although the language of article VIII, section 5 grants the legislature authority to bestow jurisdiction on statutorily created courts, City of Monticello v. Christensen, 788 P.2d 513, 518 (Utah), cert. denied, 498 U.S. 841, 111 S.Ct. 120, 112 L.Ed.2d 89 (1990), it does not give the legislature the discretion to determine who has the authority to exercise that jurisdiction. Thus, while the circuit court clearly had jurisdiction to decide this matter, it does not necessarily follow that the circuit court commissioner had authority to enter judgment and impose sentence in her capacity as a circuit court commissioner.
By enacting section 78 — 3—31(l)(a) and (6)(a), the legislature has attempted to grant authority to enter final judgments and impose sentence in courts of record to nonjudg-es, in violation of article VIII of the Utah Constitution. Such a grant is plainly unconstitutional because, pursuant to article VIII, only judges may enter judgments and impose sentence in courts of record since they are the only judicial officers constitutionally appointed to perform such functions. Moreover, as stated in Justice Howe’s concurring opinion, the fact that Ohms signed a waiver and consent form is irrelevant to our analysis because “it [was] not within his power to invest by a ‘waiver’ the right to perform core judicial duties in persons to whom that right has not been granted by [article VIII,] section 4.” Accordingly, we conclude that section 78-3-31 violates the Utah Constitution insofar as it attempts to vest authority to enter final judgments and impose sentence in criminal misdemeanor cases, which are core judicial functions, upon persons other than article VIII judges.20
III. DE FACTO AUTHORITY
However, because the circuit court to which the commissioner was assigned had jurisdiction to decide this matter, we must address Commissioner Peuler’s authority to hear this case as a “judge de facto” of the third circuit court.
A judge de facto is defined as:
One who holds and exercises the office of a judge under color of lawful authority and by a title valid on its face, though he has not full right to the office, as where he was appointed under an unconstitutional statute, or by an usurper of the appointing power, or has not taken the oath of office.
[854]*854Black’s Law Dictionary 841 (6th ed. 1990); see also State ex rel. Farmer v. Edmonds Mun. Court, 27 Wash.App. 762, 621 P.2d 171, 175 (1980) (holding that when a judicial office “is created by legislative act or municipal ordinance ... the office is regarded as a de facto office until the act or ordinance is declared invalid”); accord O’Neill v. O’Neill, 420 So.2d 261, 263 (Ala.Civ.App.), affd sub nom. Ex Parte O’Neill, 420 So.2d 264 (Ala.1982); Mitchell Mill Remnant Corp. v. Long, 223 Ky. 242, 3 S.W.2d 639, 639 (1928); Sheldon v. Green, 182 Okla. 208, 77 P.2d 114, 115-16 (1938).
This court has defined an officer de facto as follows:
“An officer de facto is one whose acts, though not those of a lawful officer, the law, upon principles of policy and justice, will hold valid so far as they involve the interests of the public and third persons, where the duties of the office were exercised,
First, without a known appointment or election, but under such circumstances of reputation or acquiescence as were calculated to induce people, without inquiry, to' submit to or invoke his action, supposing him to be the officer he assumed to be.
Second, under color of a known and valid appointment or election, but where the officer had failed to conform to some precedent requirement or condition, as to take an oath, give a bond, or the like.
Third, under color of a known election or appointment, void because the officer was not eligible, or because there was a want of power in the electing or appointing body, or by reason of some defect or irregularity in its exercise, such ineligibility, want of power, or defect being unknown to the public.
Fourth, under color of an election or appointment by or pursuant to a public unconstitutional law, before the same is adjudged to be such.”
Vance v. Fordham, 671 P.2d 124, 131 n. 5 (Utah 1983) (emphasis added) (quoting State v. Carroll, 38 Conn. 449, 471-72 (1871)), cert. denied sub nom. Vance v. Utah, 465 U.S. 1025, 104 S.Ct. 1280, 79 L.Ed.2d 684 (1984); see also State v. Menzies, 845 P.2d 220, 226 (Utah 1992) (stating that under de facto officials doctrine, persons “may be considered de facto officials if they assume official authority under color of a valid appointment and public acquiescence in the authority”); Hussey v. Smith, 99 U.S. 20, 24, 25 L.Ed. 314 (1878) (stating that “[a]n officer de facto is not a mere usurper, nor yet within the sanction of law, but one who, colore officii, claims and assumes to exercise official authority, is reputed to have it, and the community acquiesces accordingly”); accord 46 Am.Jur.2d Judges § 243 (1969). Although Vance did not specifically address judges de facto, but rather a member of a committee recommending revocation of the license of a doctor who lacked statutory qualification, the court nonetheless stated in broad language that when an officer lacks authority to perform the duties he or she has performed but acts as an officer de facto, the action taken by that officer is valid. Vance, 671 P.2d at 130-31.
Also of note is this court’s decision in In re Thompson’s Estate, 72 Utah 17, 269 P. 103 (1927), which rejected a petition for rehearing that objected to a district judge’s sitting on the state supreme court following a justice’s death but before a new justice was named and sworn in. The court held that the district judge had, at least, de facto authority to sit with the supreme court, given that (1) the district judge had authority in other instances to sit with the court, and (2) the parties had knowledge of and did not object to the district judge’s participation. Id. at 87, 269 P. at 128.
In light of the above authority, it is clear that although the statute granting commissioners authority to enter final judgments and impose sentence must be declared unconstitutional, actions taken by commissioners in the past are not subject to challenge since court commissioners in those cases acted with de facto authority. See, e.g., Farmer, 621 P.2d at 175 (holding that judgments rendered by courts not having authority to enter such are not subject to collateral attack because judges entering those judgments were de facto officers).
However, it would be unconscionable to deprive Ohms, who has sustained the bur[855]*855den of attacking an unconstitutional statute, of the fruits of victory, thereby discouraging challenges to statutes of questionable validity. See Rio Algom Corp. v. San Juan County, 681 P.2d 184, 196 (Utah 1984). In cases like the one at bar, “considerations of judicial integrity require us to extend the benefit of our decision to [the] petitioner.” Labrum v. Utah State Bd. of Pardons, 870 P.2d 902, 914 (Utah 1993). Accordingly, we do not apply the de facto authority doctrine to Ohms’ ease. See Rio Algom, Corp., 681 P.2d at 196.
IV. CONCLUSION
In conclusion, we hold that Utah Code Ann. § 78-3-31 (1992) is unconstitutional to the extent that it purports to vest ultimate judicial power of courts of record in persons who have not been duly appointed as article VIII judges pursuant to the requirements of the Utah Constitution. Specifically, we hold that section 78-3-31 violates the Utah Constitution by granting commissioners the ultimate judicial power of entering final judgments and imposing sentence in criminal misdemeanor cases. Ohms’ conviction is reversed, and this matter is remanded for further proceedings consistent with this opinion.
STEWART, Associate C.J., concurs.