Justice HECHT,
delivered the opinion of the Court, in which
Chief Justice PHILLIPS, Justice ENOCH, Justice OWEN, Justice HANKINSON, Justice O’NEILL, Justice JEFFERSON, and Justice RODRIGUEZ joined.
Four cases challenging the constitutionality of the State’s congressional districts in light of the 2000 decennial census, all involving essentially the same issues, parties, lawyers, and witnesses, were set for trial on the same day, September 10, 2001, two in a district court in Travis County1 and two in a district court in Harris County.2 Before us are two interlocutory appeals from the cases in Travis County, an original mandamus proceeding arising out of the cases in Harris County, and motions to stay the trials in all of the cases. The central dispute is over which of the two district courts has dominant jurisdiction and should proceed to trial first. We hold, for reasons that we explain, that the district court in Travis County has dominant jurisdiction and should proceed to trial immediately, and that the district court in Harris County should abate the cases pending there. We conditionally grant the petition for writ of mandamus in No. 01-0827 and dismiss the interlocutory appeals in No. 01-0728 and No. 01-0810 as moot. The stays we previously issued.are lifted. Because of the importance of completing the trial with dispatch, no motions for rehearing will be entertained.3
I
The members of the United States House of Representatives must be “apportioned among the several States according to their respective numbers”4 as determined by the decennial census.5 As a result of the 2000 census, Texas is entitled to two additional congressional delegates, and thus the State’s congressional districts must be redrawn. Although the United [243]*243States Supreme Court has held “[fjrom the beginning” that redistricting “ ⅛ primarily a matter for legislative consideration and determination,’ ”6 the 77th Legislature this year adjourned its regular session without redrawing congressional districts, and the Governor has notified the presiding officers of that body that he will not reconvene it in special session to consider redistricting “at this time”.7 It therefore falls to the courts — first the Texas courts and then those of the United States — to reconstruct the State’s congressional districts.8 The federal courts must defer, but only for a reasonable time, and may set a deadline for state courts to act.9 That deadline, set by the United States District Court for the Eastern District of Texas in three of the five congressional redistricting cases filed in federal courts this year, is October 1, 2001, after which the federal court has stated that if no state redistricting plan is adopted it will proceed in its own cases to minimize the “risk of disrupting and delaying elections”.10
Five congressional redistricting cases, all raising essentially the same issues, have been filed in Texas courts, three in Travis County by persons identified with the Democratic Party,11 and two in Harris County by persons identified with the Republican Party.12 The Legislature has not provided adequate procedures for judicial administration to prevent undesirable forum-shopping and provide a simple means for designating a single court and judge for trial of these issues, thereby saving [244]*244taxpayers and litigants the unnecessary cost of multiple proceedings involving the same issues and preventing delay that could disrupt the 2002 elections. Therefore, we must attempt to apply general legal principles for determining dominant jurisdiction between competing trial courts to resolve the mounting disputes that threaten any final state-court resolution of congressional redistricting issues before the October 1 deadline. To do- so, we must explain in some detail the procedural history of the pending cases.
The first case, Del Rio v. Perry, was filed in Travis County on December 27, 2000.13 At that time, no official census data was available — the U.S. Secretary of Commerce did not release preliminary state-by-state figures until the next day— but the plaintiffs14 asserted that estimates by the Texas Legislative Council15 showed that Texas would be apportioned two additional congressional seats. The plaintiffs acknowledged that “the appropriate opportunity” for correcting their complaints was in the regular legislative session that would convene January 9, 2001, but alleged that there was “reason to believe” that the Legislature would deadlock over a redistricting plan. The plaintiffs asserted that the trial court could act “[i]f the State of Texas fails to enact a new congressional redistricting plan in the 2001 session, or if it enacts one that is legally inadequate”. The plaintiffs named as defendants the State of Texas, the Governor, the presiding officers of the Senate and House of Representatives, the Secretary of State, and the chairs of the Texas Democratic Party and the Texas Republican Party. All of the defendants except the Democratic Party chair filed pleas to the jurisdiction, asserting that the case was not ripe when it was filed and therefore the court lacked subject matter jurisdiction. The Democratic Party chair filed a plea in abatement, urging that the action be left pending in the event that judicial action should become warranted.
The detailed census data necessary for redistricting was not released until March 12, 2001. Prior to that date, three congressional redistricting cases had been filed in federal courts.16 Each of these cases was dismissed for lack of ripeness necessary for jurisdiction because the Legislature had not had an opportunity to adopt a redistricting plan.17 In one of the cases, dismissed on May 8, the federal court stated that “there is no threat that the Texas Legislature will fail to enact valid redistricting plans before the next election cycle begins.”18 That same day, however, the Del Rio plaintiffs amended [245]*245their petition to allege that although the Legislature had full access to the necessary census data, “there is reason to believe that the State of Texas will deadlock over congressional redistricting and fail to enact a new plan in the regular session of the Texas Legislature that is now in progress.” The plaintiffs alleged that no congressional redistricting bills had been reported out of committee, and that House rules set May 10 as the last day for the House to pass its own bills and May 18 as the last day for the House to receive Senate bills. “For all practical purposes,” the plaintiffs asserted, it was “a near-certainty” that the Legislature would fail to redraw congressional districts during its regular session.
On May 15, the district court in Del Rio heard the defendants’ pleas to the jurisdiction (excluding Speaker Laney’s) but did not announce a decision. On May 24, four days before the adjournment of the Legislature, the second state redistricting case, Associated Republicans of Texas v. Cuellar,19 was filed in Harris County. The petition alleged that “[d]ue to the rules of the Texas Legislature,” it was “almost certain that no redistricting plan of any kind will be passed by the Texas Legislature in its regular session.” The petition did not address, however, whether the rules of the House and Senate could be suspended to permit last-minute consideration of a congressional redistricting plan.20 While the plaintiffs acknowledged that it remained uncertain whether the Governor would convene a special session of the Legislature, they asserted that it was unlikely because there was “no sign that the Texas Legislature could produce a plan in a special session.” Two days later, Governor Perry wrote to Lieutenant Governor Ratliff and Speaker Laney, urging that the Legislature continue to work on redistricting after the regular session, and stating that he would call a special session once acceptable plans were produced.21
[246]*246On May 28, the Legislature adjourned sine die without having adopted a redistricting plan for the congressional delegation, the Senate, the House, or the State Board of Education. Three days later, on May 31, the plaintiffs in Del Rio again amended then- petition, noting that the Legislature had not redrawn congressional districts during its regular session, and asserting that a special session would be unlikely. These allegations were echoed in a new case filed the same day in the same court against the same defendants, Cotera v. Perry,22 the third congressional redis-trieting case to be filed in state court. Four of the defendants — the Governor, the Lieutenant Governor, the Secretary of State, and Weddington, the Republican Party chair — filed pleas to the jurisdiction asserting that Cotera was not ripe when it was filed and should be dismissed because of the real possibility on May 31 that the Governor would reconvene the Legislature in special session. Indeed, the pleas noted, it was at that time even likely that the Governor would call a special session, given that congressional redistricting plans had been enacted in special sessions in 1971,1981, and 1991.23
On June 1, the trial court in Del Rio resumed the hearing on the defendants’ pleas to the jurisdiction and at the conclusion, indicated that it would overrule them. The court signed an order to that effect on June 13. The day before the order was signed, the plaintiffs nonsuited the State of Texas, hoping to forestall an interlocutory appeal, which is allowed from an order denying a plea to the jurisdiction by a governmental unit.24 Nevertheless, the Governor, the Lieutenant Governor, and the Secretary of State filed notices of appeal. Defendant Weddington, believing that she was not entitled to appeal, petitioned this Court for review by mandamus. We denied Weddington’s petition for mandamus because she had not first presented it to the court of appeals.25 While the interlocutory appeal remained pending in the court of appeals, the plaintiff26 in Cot-era nonsuited the State of Texas as the plaintiffs had done in Del Rio, the trial court granted defendant Lane/s motion to consolidate Del Rio and Cotera, and the court overruled the defendants’ pleas to the jurisdiction in Cotera.
On August 9, the court of appeals affirmed the denial of the pleas to the jurisdiction in Del Rio.27 Although no appeal had yet been taken from the trial court’s denial of the pleas to the jurisdiction in Cotera, the court held that the plaintiffs claims in that case were clearly ripe be[247]*247cause “[o]nce the legislature adjourned ■without having passed a redistricting bill, the issue was ripe for litigation.” Then the Court concluded: “Having determined that Cotera’s claims were ripe, we need not decide the issue regarding Del Rio’s claims because the two causes are now consolidated. We must decide the appeal based upon the posture of the record before us.”28 The court also held that the appellants were entitled to take an interlocutory appeal as “governmental units” because they were sued in their official capacities.29
The Governor, the Lieutenant Governor, and the Secretary of State also appealed from the denial of their pleas to the jurisdiction in Cotera. The appellees moved the court of appeals to affirm the trial court’s rulings summarily because the very same issues had already been decided in the prior appeal. On August 31, the court of appeals dismissed the Cotera appeal for want of jurisdiction.30
Concurrent with all of the activity in the Travis County cases, litigation over the same issues in Harris County was no less active. On July 3, the fourth congressional redistricting case in state court, Rivas v. Cuellar,31 was filed in Harris County against the same defendants named in ART. The petition asserted that not only had the Legislature not enacted a congressional redistricting plan during its regular session, “neither chamber did substantial work” on a plan. The petition further asserted that “Governor Perry has announced that he will not call a special session of the Texas Legislature” — the formal announcement, as we have already said, was made on July 3,32 the very day Rivas was filed — and “[a]s a result, Texas’s congressional districts may now be redrawn only by the courts”. Rivas was later consolidated with ART, and on July 24, the trial court set a trial date of September 10. The court in Travis County had previously set Del Rio and Cotera for trial on September 17, but on August 7 it advanced that trial setting to September 10 to coincide with the trial setting in ART and Rivas. The court in Travis County consolidated the fifth state case, Connolly v. Perry,33 filed July 24, with Del Rio and Cotera, but later reversed itself in order to preserve the September 10 trial setting.
A number of parties intervened in ART and Rivas.34 Among them, Representative [248]*248Bentsen, along with three other members of Congress and others associated with the Democratic Party,35 filed a plea to the jurisdiction and a plea in abatement on August 22, asserting that the Del Rio case had dominant jurisdiction and therefore the ART and Rivas cases should either be dismissed or abated. On August 28, two other intervenors, Speaker Laney and Chairwoman Malcolm, served pleadings adopting the Bentsen group’s plea to the jurisdiction. The plaintiffs36 in the cases opposed the pleas. On August 31, the trial court overruled the pleas of the Bentsen group and Malcolm, but ordered that La-ney’s adoption of the plea to the jurisdiction be struck from the record to prevent Laney from appealing and possibly delaying the trial.
On August 10, the Governor and the Secretary of State filed a petition for review of the court of appeals’ ruling in Del Rio but did not request expedited consideration. On September 4, they also filed a petition for review of the court of appeals’ ruling in Colera. On September 5, they filed an “emergency motion” to stay the trial in the Travis County cases, arguing in part that the interlocutory appeal statute automatically stayed the commencement of trial.37 On the same day, Speaker Laney noticed an appeal from the denial of his plea to the jurisdiction in the Harris County cases,38 and the next day, September 6, the Bentsen group filed a petition for mandamus and “emergency” request to stay the trial in the Harris County cases. The “emergency” request, like the “emergency motion”, was based in part on the interlocutory appeal statute.
On Friday, September 7, we stayed the trials in both counties, requesting that both district courts remain ready to proceed on further order of this Court, and scheduled argument on all pending matters for September 10 at 10:00 a.m.39
II
Central to resolving all three petitions before us are these three issues: first, can a court have subject matter jurisdiction of a claim that was not ripe when the case was filed but became ripe while the case was pending? second, does a case filed on a claim that is not yet ripe have dominant jurisdiction over a case filed on the same claim after it has become ripe? and third, when did the challenges to the existing congressional districts in the four cases here become ripe? We discuss each in turn.
Our discussion is further complicated by the differences in the views of the parties aligned on the Republican side of the redistricting claims and the parties aligned on the Democratic side. For ease of reference only, and without dismissing the differences on each side, we refer to the Republican group generally as “petitioners”, because they join for the most part in the arguments made by the petitioners in [249]*249the interlocutory appeals, and we refer to the Democratic group generally as “rela-tors”, because they join mostly in the arguments made by the relators in the original mandamus proceeding.
A
No one questions that federal constitutional challenges to the existing congressional districts in Texas are now ripe for decision, given that Texas is entitled to two additional seats and no doubt remains that the Legislature will not redistrict. What the parties here dispute is whether a case filed when such challenges were not ripe must be dismissed for want of jurisdiction after it has become ripe.
Ripeness is one of several categories of justiciability.40 A threshold question is whether federal or state law determines the ripeness of federal constitutional claims like those made in the four pending cases. In determining standing, another justiciability issue,41 the United States Supreme Court has said that “state courts are not bound to adhere to federal standing requirements.”42 With federal constitutional rights at issue, we have sometimes sought guidance on ripeness issues in more extensively developed federal jurisprudence,43 but we have done the same with standing issues without ceding the authority of state law.44 We are inclined to think that ripeness, like standing and other justi-ciability issues, should be determined by state law, as long as applying state law does not defeat what Professor Wright has called “the uncertainly defined obligation of state courts to provide a remedy for federal wrongs,”45 but as it applies here at least, we see no difference between our law and federal law.
The Supreme Court has characterized ripeness as “peculiarly a question of timing.”46 Summarizing federal case law, Professor Wright has explained: “Ripeness doctrine is invoked to determine whether a dispute has yet matured to a point that warrants decision. The central concern is whether the case involves uncertain or contingent future events that may not occur as anticipated, or indeed may not occur at all.”47 Ripeness concerns not only whether a court can act— [250]*250whether it has jurisdiction — but prudentially, whether it should.48 In assessing ripeness, the Supreme Court has said, a court is required “to evaluate both the fitness of the issues for judicial decision and the hardship to the parties of withholding court consideration.”49 The Supreme Court has indicated that ripeness should be determined at the time of adjudication.50 As Professor Wright has explained: “Ripeness should be decided on the basis of all the information available to the court. Intervening events that occur after decision in lower courts should be included, just as must be done with questions of mootness.”51 Petitioners argue that federal law permits the consideration of post-filing circumstances only in determining prudential ripeness, not in determining the ripeness required for jurisdiction, but we cannot find that distinction in the cases. Neither did the United States District Court for the Eastern District of Texas in rejecting the argument in three of the pending federal congressional redistricting cases “that subsequent events cannot ripen a dispute if the dispute was unripe when the case was filed.”52
These principles of federal law are consistent with our own ripeness jurisprudence. In Patterson v. Planned Parenthood, we stated that “the ripeness doctrine serves to avoid premature adjudication.” 53 Quoting Professor Wright, we stated that “[r]ipeness thus focuses on whether the case involves ‘uncertain or contingent future events that may not occur as anticipated, or indeed may not occur at all.’ ”54 Ripeness, we said, involves both jurisdictional and prudential concerns.55 We did not suggest in Patterson that the ripeness required for jurisdiction must be determined only as of the date a case is filed; on the contrary, we considered evidence of circumstances after that date. The issue was whether a state appropriation rider conflicted with federal regulations. Testimony at trial reflected that neither the state agency with responsibility for the funds nor the federal agency with responsibility for the regulations [251]*251had yet determined what actions it would take.56 The trial court held that the rider was unconstitutional.57 On direct appeal, the plaintiff did not argue that circumstances had changed. We reversed, concluding that “[b]ecause its alleged injury remains contingent, [the plaintiffs] claim is not yet ripe for review.”58
Petitioners point to our statement in Waco Independent School District v. Gibson59 that “[u]nder the ripeness doctrine, we consider whether, at the time a lawsuit is filed, the facts are sufficiently developed ‘so that an injury has occurred or is likely to occur, rather than being contingent or remote.’ ”60 But that statement must be taken in the context of that case, where the only issue raised was ripeness at the time the case was filed. The plaintiffs in Gibson sued to enjoin a school district from implementing “a student-promotion policy requiring students in first through eighth grades to obtain a satisfactory score on one of two standardized assessment tests to advance to the next grade.”61 The trial court dismissed these claims on the pleadings because of the plaintiffs’ failure to exhaust administrative remedies, but the court of appeals reversed.62 We held that the school district could challenge on appeal for the first time the lack of ripeness of the plaintiffs’ claims, and that those claims, as pleaded, were not ripe. Because of the procedural posture of the case, our decision was necessarily based on the plaintiffs’ pleadings. We did not say that the time of filing was the only period ever relevant to ripeness.
Patterson and Gibson both support the proposition that a case which is not ripe when filed may be dismissed, especially if the likelihood that it will soon become ripe cannot be demonstrated. The district court could properly have dismissed Del Rio for lack of ripeness while the Legislature was still considering redistricting during the regular session, just as the United States District Courts for the Eastern and Western Districts of Texas dismissed the first three congressional redistricting cases for lack of ripeness.63 But just as a case may become moot after it is filed, it may also ripen. After the claims in Del Rio ripened, the district court was not required to dismiss the case simply because it was filed prematurely. The mischief of a contrary rule is readily apparent: a party could delay raising the issue, even until appeal, and still insist upon dismissal for want of jurisdiction at the time the case was filed, even though the issues had long since matured and been fully litigated.
Under federal law, Professor Wright concludes:
Ripeness cases have generated a functional approach that directly weighs the importance of the interest advanced; the extent of the injury or risk; the difficulty of deciding the substantive is[252]*252sues and the allied need for specific factual illumination; and the sensitivity of the issues in relation to future cases, the states, and other branches of the federal government.64
The ripeness doctrine is no less functional under Texas law.
Accordingly, we hold that a claim’s lack of ripeness when filed is not a jurisdictional infirmity requiring dismissal if the case has matured.
B
The challenges to the State’s congressional districts in all four cases set for trial are now ripe, as all parties agree. Adjudication need not, indeed must not, be delayed further. The parties dispute whether Del Rio, ART, and Cotera were ripe when filed, but relators argue that even if Del Rio was filed before the issues ripened, it should be tried first because it was filed first. We disagree.
It is not unusual for parties with a choice of forums to prefer one over another, and when more than one party can sue on the same subject matter, they may choose difference courts. As a rule, when cases involving the same subject matter are brought in different courts, the court with the first-filed case has dominant jurisdiction and should proceed, and the other cases should abate.65 The obvious reasons for abatement, as we explained in Wyatt v. Shaw Plumbing Co., are the conservation of judicial resources,66 avoidance of delay,67 “comity, convenience, and the necessity for an orderly procedure in the trial of contested issues”68 — or as we put it in Cleveland v. Ward, to “prevent races from court to court by vigilant counsel”.69 The first-filed rule also has several justifications. The jurisprudential reason for the rule is that once a matter is before a court of competent jurisdiction, “its action must necessarily be exclusive” because it is “impossible that two courts can, at the same time, possess the power to make a final determination of the same controversy between the same parties.”70 A pragmatic justification for the first-filed rule is efficiency: proceedings earlier begun may be expected to be earlier concluded. A further justification is simple fairness: in a race to the courthouse, the winner’s suit should have dominant jurisdiction. The first-filed rule admits of exceptions when its justifications fail, as when the first court does not have the full matter before it, or when conferring dominant jurisdiction on the first court will delay or even prevent a prompt and full adjudication, or when the race to the courthouse was unfairly run. Thus, in Wyatt we stated that the first-filed rule would not apply if a party’s conduct estops him from asserting dominant jurisdiction, if joinder of parties is infeasible or impossible, or if the plaintiff in the first ease is not intent on prosecuting his claims. A party who files suit on manifestly unripe claims, merely to win a race to the courthouse, falls within the first exception. Having filed claims that clearly cannot be prosecuted, he should be estopped from arguing dominant jurisdic[253]*253tion. Indeed, as we have just explained, such a case might well be dismissed. To apply the rule in that case would encourage the intentional filing of unripe claims, wasting the court’s and parties’ resources. But even if a plaintiff sues on unripe claims in good faith, intending to prosecute them, we think the first-filed rule should not apply. Conferring dominant jurisdiction on a court with such a case does nothing to promote a prompt adjudication because unmatured claims cannot be prosecuted regardless of the plaintiffs intent. And a party who jumps the gun can hardly argue that he should win the race because he meant well. By the same token, however, we see no reason to prohibit a party who files a ripe claim, either in a new suit or by amended pleading in an existing suit, from proceeding first simply because he earlier filed the same claim before it was ripe. In such circumstances the amended pleading should be treated for purposes of determining dominant jurisdiction as a new suit as of the time it is filed, but not relating back to the commencement of the action.71
Consistent with the justifications for the first-filed rule, we hold that dominant jurisdiction cannot be conferred on a court by the filing of a claim, either by an original or amended pleading, unless the claim was ripe when the filing was made.
C
From what we have concluded thus far, the court with the first ease that was ripe when filed has dominant jurisdiction and should proceed immediately to trial, and the other cases should be abated. We must now determine which case that is. As we have said already, “[r]ipeness ... focuses on whether the case involves ‘uncertain or contingent future events that may not occur as anticipated, or indeed may not occur at all,’ ”72 and requires that we “evaluate both the fitness of the issues for judicial decision and the hardship to the parties of withholding court consideration.” 73
The claims made in the four cases set for trial that congressional districts must be judicially redrawn have two basic predicates. One relates to the structure of the districts. The claimants allege that existing districts are too few, that Texas should have two more than the thirty now in place. The claimants also allege that the population of the districts varies more than the United States Constitution permits. Even assuming that either allegation could be proved without the decennial census, the policy of Article I, Section 2 of the Constitution is that the determination be based on the census. As the Supreme Court stated in Reynolds v. Sims:
Limitations on the frequency of reapportionment are justified by the need for stability and continuity in the organization of the legislative system, although undoubtedly reapportioning no more frequently than every 10 years leads to some imbalance in the population of districts toward the end of the decennial period and also to the development of resistance to change on the part of some incumbent legislators.74
Thus, whether existing districts are improperly structured depends on the 2000 census data. Preliminary data showing [254]*254that Texas is entitled to two additional seats was not released until December 28, 2000, and while many predicted that that would be the result, as the Texas Legislative Council did early in 2000, it could not be established without official census data. More detailed census data necessary to draw districts with roughly equal populations were not released until March 12, 2001. Thus, the Del Rio case was not ripe when it was filed on December 27, 2000, because the information necessary to prove the claims asserted and obtain a remedy did not exist at that time. Any attempt to redraw congressional districts prior to March 12, 2001, could only have been based on pure speculation. We note that the federal courts dismissed all three of their cases filed before that date.75
The second basic predicate of the claims for judicial relief is that legislative relief is not forthcoming. Redistricting, as we have noted above, “ ⅛ primarily a matter for legislative consideration and determination.”’ 76 Most often it is a highly charged political enterprise into which courts must not intrude except as a last resort. Determining when that day has arrived is fraught with uncertainty, as the cases before us illustrate. The plaintiffs in Del Rio alleged nearly two weeks before the Legislature’s regular session opened that there was “reason to believe” that it would deadlock on redistricting issues. That may have been a reasonable prediction at the time despite the fact that the Legislature did not deadlock on congressional redistricting in 1971, 1981, or 1991. On May 8, the plaintiffs in Del Rio amended their petition to allege that legislative inaction was “a near-certainty” because of impending deadlines set by Senate and House rules. Yet that same day the federal court in its first ART case concluded that there was “no threat” that the Legislature would fail to act before the next election cycle and dismissed the case for lack of ripeness.77 Indeed, both houses continued to suspend self-imposed deadlines. For example, on May 11 the House suspended not only its own rules but the requirement of the Texas Constitution that bills be read on three different days before passage,78 allowing a large number of bills to pass.79 That same day the Senate, too, suspended its rules to allow the introduction of a new bill.80 Action within the regular session was certainly far less likely on May 24 when ART was filed, although it remained a possibility if a plan could be agreed on. Even on May 26, two days before the regular session was to adjourn, the Governor would say only that “a special session may be necessary”. At least as far as legislative rules were concerned, passage was still possible. On May 27, the House suspended all its rules to take up eighteen conference committee reports filed after the stated deadline.81 When [255]*255Cotera was filed on May 31, three days after the regular session adjourned, there was some reason to think that a redistricting plan might be adopted in a special legislative session, as was done in 1991, 1981, and 1971.
While the ripeness of a claim for judicial redistricting requires a showing of legislative inaction, the difficulties with such a showing are formidable. First, no one can speak with authority about what the Legislature will and will not do. That body can speak only through a vote of its members, who may themselves change positions. Second, predictions about the probable course of the legislative process are notoriously unreliable, as anyone remotely familiar with the process well knows. Third, courts should not encourage parties to predict, much less prove the improbability of, legislative inaction on the important matter of redistricting. Every encouragement, at least from the judiciary, should be toward adoption of a legislative solution. Fourth, parties should not be encouraged to enlist participants in the legislative process to show that claims are ripe or not ripe. No person involved in the legislative process should be encouraged to take or defer action in order to give an appearance that a case is or is not ripe. We do not suggest that any of these problems have arisen with the pending cases; we list them only as potential difficulties in proving legislative inaction. Finally, courts— federal and state — cannot defer so long in hopes of legislative action that the election process is disrupted.
The only “hard and fast” deadline in the chronology of events was the one set by the Texas Constitution: that the Legislature adjourn sine die not more than 140 days after its regular session commenced.82 Enactment of legislation remained within the Legislature’s power until hours before adjournment, and thus inaction remained uncertain and contingent until the end of the session. Redistricting issues were not fit for judicial determination until the Legislature had its full regular session to discharge its redistricting responsibility. Once the regular session adjourned, a reasonable opportunity remained for fully litigating redistricting issues. To delay judicial proceedings further in case a special session might be called would have increased the threat of disruption to the election cycle. In sum, applying settled rules of ripeness, we conclude that the constitutional challenges to congressional districting became ripe at the end of the regular session, but not before.
Petitioners argue that a third factor should also be considered in determining ripeness in this context — the imminence of disruption to the election cycle. We agree that this is a relevant concern, although it is certainly no easier to assess than the prospect of legislative inaction. According to the United States Supreme Court, once a state legislature has had a chance to resolve redistricting issues, state courts must have a reasonable opportunity to resolve disputes, followed by federal courts.83 In Texas, any state solution requires preclearance by the United States Department of Justice under the Voting Rights Act,84 a process that often takes months. The filing period for candidates begins in early December,85 and the party primaries are in March.86 Ideally, state litigation should therefore be completed [256]*256well before October, but how much earlier it should commence in order to meet that deadline is uncertain. The pending cases illustrate that the risk of disruption to the election cycle increases dramatically if commencement of active litigation is delayed after the conclusion of the Legislature’s regular session.
For the future, we think that the difficulties in determining the ripeness of such challenges are best resolved by a bright-line rule — a set time after which judicial proceedings may be commenced and actively prosecuted, even if legislative action remains a possibility. The most appropriate deadline is the adjournment of the Legislature’s regular session. Even though it is quite possible that the Legislature will adopt a redistricting plan afterward in special session, as it has often done before, to preclude commencement of judicial proceedings any longer and still allow for a trial, appeals, preclearance under the Voting Rights Act,87 and federal court proceedings, presents an unjustifiable risk of disruption to the election cycle. It may be that in other states a bright-line rule would have less to commend it,88 but in Texas, with regular legislative sessions being relatively short, special sessions being subject to the will of the Governor, the absence of legislated procedures to streamline judicial proceedings to prevent problems such as those now before us, and the limitations on this Court’s review of factual disputes like those invariably raised in a weighing of circumstances, a bright-fine rule of ripeness based on sine die adjournment of the regular legislative session appears to best resolve the attendant problems. Of course, should the Legislature adopt a redistricting plan in special session, the courts should defer to that plan if it is legal. But otherwise the court action should proceed to trial and appeal so that a final decision can be made in the state system in time for any review in the federal courts and under the Voting Rights Act.
For this case, however, applying settled ripeness law, we hold that the constitutional challenges to congressional districts made in the cases awaiting trial were not ripe until the regular session of the Legislature after the decennial census adjourned. The first case filed after that date was Cotera, and an amended petition in Del Rio was filed the same day. The district court in Travis County therefore has dominant jurisdiction.
Ill
It remains for us to determine what relief should be granted in the three matters before us. Petitioners in No. 01-0728 request that we reverse the court of appeals in Del Rio and dismiss that case for want of jurisdiction. That request is mooted by our conclusion that the trial court has jurisdiction in Del Rio, and accordingly we dismiss the petition for review. Petitioners in No. 01-0810 request that we reverse the court of appeals’s dismissal of the appeal related to Cotera and remand the case to that court for consideration of petitioners’ arguments that the trial court lacks jurisdiction. That request, too, is mooted by our analysis above, and we likewise dismiss that petition for review. The parties have questioned whether trial is stayed by section 51.014(b) of the Texas Civil Practice & Remedies Code because of the pendency of interlocutory appeals in this Court and in [257]*257the First Court of Appeals in Houston. Because today’s decision moots the issues in all such appeals, the statutory issue is removed.
Relators request that we grant mandamus relief directing the trial court in Harris County to abate proceedings in ART and Rivas, the two cases pending there. Petitioners argue that relators’ petition for mandamus, like Weddington’s filed July 24, should be denied because it was not first presented to the court of appeals.89 But we are more than seven weeks closer to the federal court’s October 1 deadline for state-court action than we were when Weddington’s petition was filed. Time has simply run out. Under these circumstances, we must consider re-lators’ petition in the first instance.90
To obtain relief, relators must show that the trial court clearly abused its discretion and that they have no adequate remedy by appeal.91 Our determination that the Cotem court has dominant jurisdiction is based on settled principles, even though their proper application may not have been clear. As we have explained, the circumstances on which the claims that have been asserted are predicated were not sufficiently developed until the regular session of the Legislature adjourned, but they did not remain contingent until the Governor’s final announcement that he would not convene a special session. Under the law, ART and Rivas must be abated, and the district court’s failure to follow that law, even though its application was uncertain, was a clear abuse of discretion. Because “[a] trial court has no ‘discretion’ in determining what the law is or applying the law to the facts,”92 a trial court’s “erroneous legal conclusion, even in an unsettled area of law, is an abuse of discretion.”93
We stated in Walker v. Packer that an appellate remedy is inadequate, justifying issuance of mandamus relief, “ ‘when parties stand to lose their substantial rights.’ ”94 In the current circumstances, further confusion or delay in the trial of the pending challenges to congressional districting poses the very real threat that the parties will not be able to obtain a decision in the state courts that is final on appeal before the October 1 deadline set by the federal courts. Although counsel assured us at oral argument that they and the two district courts involved have cooperated in an effort to conduct two trials of the same issues, we think the inefficiency of such an approach and the uncertainty that will attend two appeals and a final appeal to this Court pose an intolerable risk to completing the process within the limited time remaining. The Supreme Court has recognized that the right of a state’s citizens to have districts drawn by state institutions is so substantial that federal courts must reasonably accommodate the state process and defer to a state solution.95 We believe that protection of this right necessitates the issuance of mandamus relief here.
[258]*258Furthermore, in CSR Ltd. v. Link, we recognized that exceptional circumstances may make a right of appeal inadequate.96 The circumstances presented here clearly fall within that category. The importance of achieving a decision of the districting claims that is final on appeal by the deadline set by the federal court and in time for review under the Voting Rights Act, all so as to minimize the risk of disruption to the impending election cycle, makes the issuance of mandamus relief not only appropriate but imperative.
Finally, in Curtis v. Gibbs, we held that mandamus is appropriate to resolve disputes over dominant jurisdiction.97 In Abor v. Black, we declined to grant mandamus relief directing a court to abate a case in deference to another court’s dominant jurisdiction absent “any order [of the former court] which actively interferes with the exercise of jurisdiction” by the court with dominant jurisdiction.98 Even under this more restrictive test, relators do not have an adequate remedy by appeal. The district court’s order in ART and Rivas setting those cases for trial at the very same time that Del Rio and Cot-era are set for trial actively interferes with the dominant jurisdiction in the latter cases. We recognize, of course, that trial was first set in Harris County on September 10, and that the district court in Travis County later advanced the trial setting to the same date, but as we have concluded, the court in Travis County has dominant jurisdiction and should proceed first. It is unimportant to the issue of dominant jurisdiction which court first set an earlier trial date.
“Courts are erected to settle controversies, not to multiply them.”99 Accordingly, we grant the relators’ request that the district court in Harris County be directed to abate proceedings in ART and Rivas. We are confident that the district court will promptly comply, and our writ will issue only if it does not.
Justice BAKER issued a dissenting opinion.