In Little v. Hecox, one of the most-watched cases of the Supreme Court’s 2025-26 term, the cert petition granted by the Court presents the question of “[w]hether laws that seek to protect women’s and girls’ sports by limiting participation to women and girls based on sex violate the Equal Protection Clause of the Fourteenth Amendment.”1 But it now looks like the Court won’t (or at least shouldn’t) answer that question (at least not in the context of the Hecox dispute), because the case has become moot.
The plaintiff, Lindsay Hecox, initiated the litigation in federal district court over five years ago, in April 2020.2 Hecox is a transgender woman who professed a desire to compete on the women’s track and cross-country teams at Boise State University (“BSU”), where she was and remains a student.3 Her lawsuit challenged the constitutionality of the Idaho Fairness in Women’s Sports Act (“the Act”),4 which requires sports programs at various educational institutions to “designate,” “based on biological sex,” which students may participate, and prevents sports programs that are “designated for females, women, or girls” from being “open to students of the male [biological] sex.”5 Hecox sought injunctive relief but not damages, and named as defendants, among others, Idaho Governor Bradley Little, BSU’s president, and various state educational officials.6 Concluding that heightened scrutiny would apply to the Act under the Equal Protection Clause of the Fourteenth Amendment, the district court preliminarily enjoined the challenged statute in August 2020.7 In June 2024, the U.S. Court of Appeals for the Ninth Circuit (in an amended opinion) affirmed that injunction as applied to Hecox.8 The defendants then filed, on July 11, 2024, a petition for certiorari, which Hecox opposed but which the Supreme Court granted almost a year later, on July 3, 2025,9 shortly after the Court issued its ruling in United States v. Skrmetti.10
There things stood until two months ago, when, on September 2, 2025, Hecox, represented by the ACLU and other experienced appellate lawyers, filed with the Supreme Court a “suggestion of mootness” in her case.11 The filing explained that as a result of her own illness, her father’s death, negative publicity associated with the litigation, and her desire to focus on completing her graduation requirements, Hecox had “decided to permanently withdraw and refrain from playing any women’s sports at BSU or [any other institution covered by the Act], and represented that she is “firmly committed not to try out for or participate in any school-sponsored women’s sports covered by [the Act].”12 Consistent with these representations, Hecox filed (and told the Court that she had filed) with the district court a Notice of Voluntary Dismissal under Federal Rule of Civil Procedure 41 to dismiss her entire complaint with prejudice (that is, without holding the door open to reinstituting the lawsuit).13 In light of Hecox’s decision to cease playing any women’s sports covered by the Act, she argued to the Court, her case was now moot and (in light of the dismissal with prejudice and her sworn statement committing never to play sports covered by the Act again) her claims against the defendants could not be revived or recur.14 As a result, she suggested, the Court should vacate on mootness grounds the Ninth Circuit’s judgment in her favor, and remand with a direction to dismiss the appeal.15 If that course of action were pursued, Hecox stated, the defendants would “suffer no prejudice.”16
The defendants pushed back. They filed a motion in the district court opposing dismissal (and indeed seeking to strike the Notice of Voluntary Dismissal) on the ground that Hecox had previously agreed to stay all “proceedings” in the district court while the case was on review at the Supreme Court.17 In agreeing to that stay, defendants argued, Hecox had waived her right to dismiss, because a dismissal entailed a “proceeding.”18 The defendants (as petitioners) also filed in the Supreme Court a response to Hecox’s suggestion of mootness, in which they argued the case is not moot and should be resolved by the Court on the merits for the following reasons: dismissal cannot occur because of the agreed-to stay of district court proceedings; Hecox (still a student at BSU) might change her mind in the future and seek to play in women’s sports covered by the Act, so that her dispute might come back to life; the Ninth Circuit’s decision in Hecox’s case has already been invoked as precedent in other Ninth Circuit cases; and Hecox has engaged in (improper) “gamesmanship” to avoid Supreme Court review of the lower court ruling.19
While these various filings raise several intriguing (and potentially vexing) problems of federal jurisdiction and procedure, the most appropriate analysis indicates (as we explain below) that the case is indeed moot, and that the Supreme Court should, as Hecox suggests, dismiss with a direction to the Ninth Circuit to vacate its judgment.
The concept of mootness, the Supreme Court has explained, reflects the constitutional requirement that federal courts resolve the merits of disagreements only when those disagreements are housed within “cases” and “controversies,” and the corresponding limitation that federal courts refrain from issuing rulings in disputes that are not alive within the meaning of Article III.20 The Court has instructed that “[a] case is moot when the issues presented are no longer ‘live’ or the parties [now] lack a cognizable interest in the outcome” even if they once had one.21 Crucially, the Court has insisted that “an actual controversy . . . exist not only at the time the complaint is filed, but through all stages of the litigation.”22 Thus, as the Court has repeatedly observed, it cannot review a case that has become moot even late on the way to the Court’s final resolution because “[t]o sustain our jurisdiction . . . it is not enough that a dispute was very much alive when suit was filed, or when review was obtained in the Court of Appeals.”23
There are, of course, many reasons a once-live case might become moot. Cases (like Hecox’s) brought by students seeking (only) injunctive relief from policies at their educational institutions—for example, challenges to campus rules regulating student speech—are particularly prone to mootness because students (hopefully) graduate and (unless they plan to enroll in other university programs) upon graduation an injunction against the university would thus have no effect on them.24
Although mootness is grounded in Article III limitations on judicial authority, the Court sometimes appears reluctant to accept that a dispute no longer exists. For example, under the “voluntary cessation by defendants” doctrine, the Court has held that “a defendant [does not] automatically moot a case simply by ending its [ostensibly] unlawful conduct once sued” if the defendant remains free and thus reasonably likely to resume the allegedly wrongful conduct against the challenger at a later date.25 Moreover, the Court has recognized some exceptions to the flat rule that moot cases must be dismissed without consideration of the merits. For example, the Court has permitted merits resolution in cases that are technically moot (including challenges by pregnant women to abortion laws and, less often, challenges to election laws) where the merits issues presented are “capable of repetition” as between the parties but (since litigation takes time) are likely to “evade” review by the Court because events in certain settings will invariably create technical mootness prior to the Court being able to fully consider and resolve the merits.26 This nod to the reality that full litigation of an acknowledged Article III case cannot be instantaneous distinguishes mootness exceptions from, say, the unwillingness of the Court to confer standing simply on the ground that if the plaintiff in a given dispute lacks standing, then no one else would ever have it either.27 In any event, the capable-of-repetition-yet-evading review exception, as important as it is,28 does not seem relevant to the Hecox matter, both because (1) Hecox (if she is to be believed or bound by her sworn statement or a dismissal with prejudice) will not have future skirmishes over the Act with the defendants; and (2) (even as to other would-be challengers) the issue of whether the Act runs afoul of the Equal Protection Clause is not likely to evade review by the Court.
Given Hecox’s sworn representations (which we have no reason to doubt and which in any event would effectively bind her and properly result in dismissal of her claims with prejudice), the Hecox case seems clearly to be moot. Voluntary dismissal of a claim with prejudice is an adjudication on the merits for purposes of res judicata.29 Although the defendants–petitioners, in their opposition to Hecox’s suggestion of mootness, express a concern that Hecox might again seek to participate in college sports in Idaho at a later date, dismissal with prejudice would bar her from bringing a future lawsuit against any of the defendants she had sued to prevent application of the Act against her. It is possible that she could enroll at a different institution in a different state (perhaps even in the Ninth Circuit) with a law similar to Idaho’s, and bring a new lawsuit naming different defendants. But that prospect does not weigh against mootness in Hecox’s Idaho case. And if, as we explain below, the Ninth Circuit decision is vacated, defendants in other states won’t be unfairly burdened by Hecox’s Idaho litigation.
So, too, we don’t think there is much to the defendants’ point that the Ninth Circuit decision in Hecox’s case has already been relied upon as precedent in other cases. That fact doesn’t support a determination of non–mootness any more than an absence of citations would support a finding that the case is in fact moot. Indeed, even if Hecox had not disclaimed any intent to participate in sports such that no mootness question were present, and the Supreme Court were to have reversed the Ninth Circuit on the merits, the other cases that had already relied on the Ninth Circuit precedent in the meantime would still exist—they simply would have no future weight. But so too they will be deprived of future weight if the Ninth Circuit ruling on which they themselves relied (that is, the Ninth Circuit’s ruling in Hecox itself) is vacated.
We also don’t think Hecox’s agreement to stay proceedings in the district court should change anything. On October 14, 2025, the district court did grant the defendants’ motion to strike Hecox’s Notice of Voluntary Dismissal,30 but the district court’s order is, to be blunt, an analytic hot mess. To its credit, the district court did acknowledge that under Federal Rule of Civil Procedure 41, “a notice of dismissal . . . is normally self-executing and that ‘[t]here is nothing the defendant can do to fan the ashes of that action into life and the court has no role to play.’”31 But the district court then qualified this latitude by saying “dismissal [can] be supplanted by other factors” such as “statutory provisions.”32 The district court found one such (important, albeit non-statutory) factor in Hecox’s case to be the “stay of proceedings” mutually requested by the parties.33 From there, the district court “[s]tepp[ed] back,” observing that it had “inherent power to control [its] docket,” and that it “s[aw] no reason suggesting why that power should not apply to dismissal notices—when necessary.”34 The court then indicated its provisional agreement with the defendants’ argument that judicial estoppel and waiver both applied: “Under the circumstances, it does seem Hecox’s position now is incongruent with her earlier position [that matters should be stayed while the case was at the Supreme Court]. . . . The Court is [also] somewhat persuaded by the idea that Hecox waived her right to file a notice of voluntary dismissal—at least temporarily.”35
Fundamentally, and putting aside the mechanical (and repetitive) quality of the district court’s reasoning, the court never demonstrated appreciation for the big picture against which Hecox’s Notice of Voluntary Dismissal must be assessed. The common thread connecting all of the district court’s analytic and doctrinal mistakes is that in the present dispute, the Notice of Voluntary Dismissal does not reflect merely a desire to stop litigating, but a change in actual facts that, unless rejected as false, moots the case and terminates the Article III power of federal courts.36 Thus, the district court’s “inherent power to control its docket” is entirely beside the point because district courts’ power to control their dockets ends at the point Article III power itself ends; a district court cannot ignore constitutional mootness simply because moot cases complicate docket management.
In a similar vein, it borders on the surreal to say that judicial estoppel prevents a party that earlier represented in the district court a ripe case or controversy (that then goes pending in a higher court) from later alerting the district court to facts indicating no such controversy continues to exist. Most obviously, a case might settle. It would be exceedingly odd to think both parties would be “estopped” from settling, notifying the court, and bringing an end to litigation simply because they had sought and obtained a stay in proceedings—indeed, as the district court itself conceded, such stays are often entered precisely in order to facilitate settlement negotiations.37 More generally, we think a Rule 41 Notice of Voluntary Dismissal is always inconsistent with the prior—if implicit—representation to the court that a plaintiff wants to litigate, and yet Rule 41 dismissals aren’t generally barred by estoppel.
But what about the notion that Hecox “waived” her right to stop litigating by agreeing to a stay of proceedings? Again, at most, such a waiver could prevent Hecox from discontinuing litigation in a dispute that remains factually ripe within the meaning of Article III. (Imagine, e.g., Hecox still wants to compete in Idaho collegiate athletics but just doesn’t want to litigate anymore.) But one could never “waive” the right to decide to stop competing athletically—what if Hecox were in an accident that clearly ended her athletic career? And unless Hecox’s factual representations in her sworn Supreme Court filing are demonstrated to be false, her change of athletic (rather than litigious) heart simply moots the case.
We think the district court’s decision to strike should be corrected, either by the Ninth Circuit or by the district court itself. For example, Hecox could first move to amend the stay given a change in facts that raises the issue of mootness, something the district court would have to permit, and then after that file the Notice of Voluntary Dismissal with prejudice. But even if the (implausible) district court decision stands, we don’t believe that would prevent the Supreme Court from doing what is right and dismissing the case that is before it as moot. Consider, in this regard, Deakins v. Monaghan.38 There, the Supreme Court ordered vacatur with respect to certain equitable claims when respondents represented to the Court that they would amend their complaint to withdraw those claims.39 Petitioners objected that despite the promise respondents made, respondents could still revive their claims in a future action.40 The Court thought otherwise—by operation of law. It explained:
Petitioners misconceive the effect respondents’ representations [in this Court] and our reliance thereon will have on the shape of the federal litigation. When a claim is rendered moot while awaiting review by this Court, the judgment below should be vacated with directions to the District Court to dismiss the relevant portion of the complaint. This disposition strips the decision below of its binding effect. And respondents can be prevented from reviving their claims by the order of dismissal. Because this case was rendered moot in part by respondents’ willingness permanently to withdraw their equitable claims from their federal action, a dismissal with prejudice is indicated. This will prevent the regeneration of the controversy by a reassertion of a right to litigate the equitable claims in federal court. Relying upon the representations of respondents’ counsel at oral argument that all . . . respondents have no continuing interest in the federal adjudication of their claims for equitable relief, the equitable claims of all respondents should be dismissed with prejudice. Respondents therefore will be barred from reviving in federal court their equitable claims against petitioners arising out of the events [at issue in the case].41
Indeed, a footnote in Deakins makes clear that it is easier to ensure that voluntary cessation of conduct by a plaintiff that moots a case is not ephemeral than it is to prevent a defendant from re-engaging in the contested activity:
The Court’s ability to prevent respondents from renewing their claims after they are dismissed as moot distinguishes this case from one in which a defendant attempts to avoid appellate review by voluntarily ceasing the challenged conduct without losing the ability to reinitiate the conduct once the mooted case is dismissed.42
Deakins would seem to compel the Court to conclude that Hecox is abandoning her claims, find mootness, and order vacatur of the Ninth Circuit ruling and dismissal with prejudice in the district court. It is most unlikely that any notion of Hecox having waived her right to dismiss (if such a right could ever be waived) while her case was at the Supreme Court could stand in the way. That assessment seems to best comport with the Court’s insistence that “[p]laintiffs are masters of their complaints and remain so at the appellate stage of a litigation,”43 and with other cases in which the Supreme Court has ordered vacatur following a respondent’s voluntary dismissal.44
As the preceding discussion indicates, however, mootness, even when its application is clearly indicated, can in some instances implicate concerns about fairness. If the facts giving rise to mootness occur after a party has lost in a United States Court of Appeals but before the Supreme Court has a had a chance to weigh in (whether by denying review or with a decision on the merits), mootness could leave the petitioning party (and those like it) stuck with the adverse circuit court ruling, which would be binding precedent in the circuit even though that circuit ruling was effectively unappealable. That’s where the device commonly associated with United States v. Munsingwear45 (invoked by Hecox in her suggestion of mootness and relied upon by the Court in Deakins) comes in. Under the Munsingwear doctrine, when intervening mootness renders a pending case moot, the decision from the lower court should ordinarily be vacated, or wiped out. As Munsingwear itself puts it:
The established practice of the Court in dealing with a civil case from a court in the federal system which has become moot while on its way here or pending our decision on the merits is to reverse or vacate the judgment below and remand with a direction to dismiss.46
By “strip[ping] the decision below of its binding effect,”47 vacatur prevents an unreviewable decision “from spawning any legal consequences.”48 (In a similar fashion, the inability to appeal may be a major factor affecting the extent to which lower court rulings are entitled to claim- or issue-preclusive effect.)49
Yet the Munsingwear rule is not quite as simple as it may sound. Munsingwear vacatur is an equitable doctrine. Not all cases become moot for the same reason, and some cases present more compelling reasons for vacatur than do others. For example, the Court has made clear that Munsingwear vacatur is not available if the party adversely affected by the decision of the lower court voluntarily caused the mootness (precluding Supreme Court review) and the other party opposes vacatur. Thus, in U.S. Bancorp Mortgage Co. v. Bonner Mall Partnership,50 the Court held vacatur unavailable when mootness resulted from the parties’ settlement of their claims, and the only party seeking to vacate the Court of Appeals ruling had lost below.51 Justice Antonin Scalia explained:
[Under Munsingwear,] [a] party who seeks review of the merits of an adverse ruling, but is frustrated by the vagaries of circumstance, ought not in fairness be forced to acquiesce in the judgment. . . . The same is true when mootness results from unilateral action of the party who prevailed below. . . . [But] [w]here mootness results from settlement, . . . the losing party [below] has voluntarily forfeited his legal remedy [of] the ordinary processes of appeal or certiorari, thereby surrendering his [entitlement] to the equitable remedy of vacatur. The judgment is not unreviewable, but simply unreviewed by his own choice.52
Notwithstanding the Bonner Mall exception, as this passage from Justice Scalia’s opinion suggests, vacatur under Munsingwear is the appropriate course of action when (as in Hecox) “mootness results from unilateral action of the party who prevailed below.”53
That leaves, then, the question of whether the Court should refuse to find mootness out of a concern that Hecox is, as defendants claim, engaging in problematic gamesmanship. The defendants assert that Hecox, who has benefited from the injunction during her time in college, is seeking to moot the case because, after Skrmetti, she has now concluded that the Court is very likely to reverse the lower court decision.54 On the defendants’ theory, Hecox and her lawyers have decided it is better to give up the favorable circuit court decision on the Idaho law than to have her lawsuit serve as the vehicle for the Supreme Court to issue an adverse ruling with nationwide effects.
The Court has on occasion expressed concerns with parties’ actions that moot a case as a means of avoiding Court review. Of particular relevance is City of Erie v. Pap’s A.M.55 In that case, the respondent, a corporation operating a nude dancing establishment, had prevailed in the Pennsylvania Supreme Court on its federal constitutional injunctive challenge to a city of Erie ordinance, and when the case reached the Supreme Court, the corporation argued mootness because the nude dancing establishment was no longer operating in the city.56 The Court rejected the claim of mootness and reversed the state Supreme Court on the First Amendment merits to hold the ordinance valid.57 Writing for the Court on the mootness issue, Justice Sandra Day O’Connor indicated that the issue was “close,” but she pointed to the possibility that the respondent, still incorporated in Pennsylvania, might well start up a nude dancing establishment again in Erie. She continued: “[o]ur interest in preventing litigants from attempting to manipulate the Court’s jurisdiction to insulate a favorable decision from review counsels against a finding of mootness.”58
City of Erie is a case that might incline some members of the Court to try to resolve the Hecox case on the merits. But that inclination would be wrong, because City of Erie was very different from Hecox in two important respects. For starters, because City of Erie came up via the state courts, Munsingwear (which involves the Supreme Court’s power to supervise lower federal courts) and vacatur pursuant to it were not available. As a result, finding the City of Erie case moot would have left the Pennsylvania Supreme Court ruling intact (unless that court, acting under a state law mechanism, itself chose to vacate) perhaps giving the respondent and businesses like it exactly what they wanted—invalidation of the Erie ordinance. And, relatedly, the City of Erie plaintiff’s ability to start up a new nude dancing operation in Erie in renewed contravention of the ordinance was, as a factual matter, unconstrained (and even facilitated by the state Supreme Court decision that remained on the books), whereas Hecox can no longer seek to avoid the strictures of the Idaho Act (because she is subject to the Act and can no longer challenge it in any court in light of her sworn stipulation and a dismissal with prejudice that would come about either by the independent action of the district court or by virtue of the Court’s reliance on her representations, as in Deakins). In that important sense, Hecox is in no way trying, in the language of City of Erie, “to insulate a favorable decision from review.”59
And even putting aside these crucial distinctions between the City of Erie case and Hecox’s, we find much to commend the concurring opinion by Justice Scalia (joined by Justice Clarence Thomas) in City of Erie, concluding that the unavailability of vacatur should not matter. Importantly, they thought the consequence of mootness—that an erroneous state court decision on a federal constitutional question remained in place—was “not a consequence that authorizes us to entertain a suit the Constitution places beyond our power.”60 If a case is moot, it is moot.61 There is a logical cleanliness to this position. Whether or not vacatur is available does not, analytically at least, seem to bear on whether the controversy remains ongoing. Indeed, only after mootness is found does the issue of vacatur even come into play. In any event, as noted above, the inability to dictate vacatur in City of Erie seems irrelevant to Hecox’s case, where there is no reason vacatur would be unavailable.
In a more recent case, Acheson Hotel v. Laufer,62 the Court returned to these issues and rightly expressed a disinclination to rest a mootness decision on possible gamesmanship. The case involved the question of whether a plaintiff had Article III standing to bring a claim against Acheson Hotel for violating the Americans with Disabilities Act (“ADA”) by failing to provide information on its website about accessibility, given that the plaintiff had no plans ever to visit the hotel.63 The plaintiff prevailed below, and the Supreme Court granted the hotel’s petition for certiorari.64 Subsequently, one of the plaintiff’s lawyers was suspended from the practice of law, and the plaintiff filed a Notice of Voluntary Dismissal to have the case (along with others she had pending against other hotels) dismissed with prejudice.65 The plaintiff then filed a suggestion of mootness with the Supreme Court.66 Acheson objected that the plaintiff (now respondent) was manufacturing mootness to prevent the Supreme Court from ruling on the standing issue, and that Acheson and other hotels would soon face similar claims by other ADA testers.67 In an opinion by Justice Amy Coney Barrett, joined by six other justices, the Court found the case to be moot and, pursuant to Munsingwear, vacated the circuit court’s judgment and ordered dismissal.68 Regarding the possibility and relevance of gamesmanship, Justice Barrett observed:
We are sensitive to Acheson’s concern about litigants manipulating the jurisdiction of this Court. We are not convinced, however, that Laufer abandoned her case in an effort to evade our review. She voluntarily dismissed her pending ADA cases after a lower court sanctioned her lawyer. She represented to this Court that she will not file any others. Laufer’s case against Acheson is moot, and we dismiss it on that ground. We emphasize, however, that we might exercise our discretion differently in a future case.69
Justice Thomas concurred in the judgment, writing that “the circumstances strongly suggest strategic behavior” on the part of the respondent, and that he “would not reward . . . [her] transparent tactic for evading our review.”70 Rather than dismiss the case as moot, Justice Thomas would have ruled that the plaintiff lacked Article III standing to bring the claim against Acheson.71
We should note a few important points about Acheson. First, the “merits” question in Acheson was itself a “justiciability” question (Article III standing), so the “discretion” to which Justice Barrett’s majority opinion referred (and that might be exercised differently in future cases) is best understood as discretion to resolve a case on one Article III ground (standing) rather than another (mootness), not the discretion to decide the substantive merits of a case that is, in fact, moot under Article III, simply because of a suspicion of gamesmanship. That is precisely the way Justice Thomas, who did reach the “merits” question in Acheson, referred to the “discretion” he was exercising.72 In neither City of Erie nor Acheson did any Justice reach (or indicate any power to reach) the substantive merits of a claim that was moot in the sense that it was no longer alive and could not be revived as between the parties. And in Hecox’s case, the possibility of any revival concerning the legal question presented (whether Idaho’s Act is unconstitutional) is a great deal weaker than it was in City of Erie, as noted above, and is also weaker than it was in Acheson, because the Acheson Court merely accepted the plaintiff’s representation she would not assert (and litigate) standing to sue other hotels that are subject to the ADA, whereas Hecox (by virtue of both her sworn statement and a dismissal with prejudice) will never be able to sue anyone to litigate the merits question presented, i.e., whether the Idaho Act violates equal protection, insofar as the defendants are the only ones responsible for enforcing the Act.
Second, the Court’s discussion of gamesmanship may obscure two separate considerations in play. One is the attempt of a party to insulate a favorable lower court ruling from Supreme Court review. But that strategic ploy can be fully addressed by vacatur (at least, as in Hecox, when a case comes up through federal, rather than state, courts). A separate concern is that parties ought not to waste federal courts’ time and resources. But as tempting as it might be for the Court to retain jurisdiction in Hecox (or other cases) to avoid wasting already-expended federal judicial resources (and we understand why the Court abhors such waste),73 that would, we think, be a mistake.
Live controversies become moot (or are never even initiated) because of rational, if strategic, decisions made by parties all the time, not just at the Supreme Court but in lower courts as well. Importantly, a gamesmanship exception to mootness would be quite different from other exceptions (such as capable-of-repetition-yet-evading-review) that the Court has recognized: It is one thing for the Court to keep an expired case to review an issue the Court will never otherwise be able (because of its own ponderous timelines) to resolve in any dispute; it is another thing entirely to keep an expired case to resolve an issue that can easily be resolved in other live cases, simply to send a message to litigants to avoid some vaguely defined subset of the kind of routine (if self-interested) litigation decisions lawyers and clients make every day.
And even if it were possible (which we doubt) to craft with any workable precision a gamesmanship exemption to mootness, such an exemption would be in direct tension with the oft-stated observation by the Court that mootness is indeed meaningfully grounded in Article III. It wouldn’t seem to matter, for Article III purposes, that the reason there is no “case” or “controversy” is that a party engaged in litigation decisions based on predictions of how a court might rule.74 Either there is a live case or there is not, and if there is not, the Court wouldn’t seem to have the power to set the law (for the entire country) simply to discourage what it might worry is problematic litigation behavior.75
The Court has deferred the issue of mootness in Little v. Hecox pending oral argument, presumably in early 2026.76 For the reasons we have set out, we think the sensible and principled course is for the Court to find the case moot and order vacatur. And we note that the Court still has on its docket this term West Virginia v. B.P.J.77 In that case, a transgender middle-school student challenged under Title IX and the Equal Protection Clause her exclusion, by operation of state law, from sports teams at her school.78 After the district court granted summary judgment for the state,79 the Fourth Circuit reversed on the Title IX claim and vacated and remanded for additional evidentiary proceedings on the equal protection claim.80 Given the presence of a statutory claim and the possible need for further development of the record, the Court might or might not get to the equal protection issue in B.P.J.81 But even if not, the principled path remains to wait for another day and another case.
* Daniel J. Dykstra Endowed Chair and Distinguished Professor of Law, UC Davis School of Law; former Dean and Iwan Foundation Professor of Law, University of Illinois Urbana-Champaign.
** Albert E. Jenner, Jr., Professor of Law and Director, Program in Constitutional Theory, History and Law, University of Illinois Urbana-Champaign.
1. Petition for a Writ of Certiorari at i, Little v. Hecox, No. 24-38, U.S. (July 11, 2024), 2024 WL 3445118.
2. Hecox v. Little, 479 F. Supp. 3d 930, 943 (D. Idaho 2020).
3. Id. at 946.
4. Idaho Code § 33-6201 (2023).
5. Id. § 33-6203(1)–(2).
6. Hecox, 479 F. Supp. 3d at 946–47.
7. Id. at 975–76, 988–89.
8. Hecox v. Little, 104 F.4th 1061, 1091 (9th Cir. 2024).
9. 145 S. Ct. 2871 (2025) (mem.).
10. 145 S. Ct. 1816, 1835–36 (2025) (holding that a Tennessee law banning puberty blockers and hormone therapy for the treatment of gender dysphoria in minors did not classify on the basis of sex or transgender status, and was therefore subject to rational-basis review under the Equal Protection Clause and most likely valid).
11. Respondent’s Suggestion of Mootness, Little v. Hecox, No. 24-38, U.S. (Sept. 2, 2025), 2025 WL 2597331.
12. Id. at 4.
13. Id.; see also Plaintiff’s Notice of Voluntary Dismissal, Hecox v. Little, No. 1:20-cv-00184 (D. Idaho Sept. 2, 2025).
14. Respondent’s Suggestion of Mootness, supra note 11, at 4–5.
15. Id. at 5 n.2.
16. Id.
17. Defendants’ Motion to Strike Purported Notice of Dismissal at 2, Hecox v. Little, No. 1:20-cv-00184 (D. Idaho Sept. 8, 2025).
18. Id. at 6.
19. Petitioners’ Response to Suggestion of Mootness at 6–12, Little v. Hecox, No. 24-38, U.S. (Sept. 26, 2025), 2025 WL 2831554.
20. See, e.g., Already, LLC v. Nike, Inc., 568 U.S. 85, 90, (2013) (“Article III of the Constitution grants the Judicial Branch authority to adjudicate [only] ‘Cases’ and ‘Controversies.’ In our system of government, courts have no business deciding legal disputes or expounding on law in the absence of such a case or controversy.”) (quotation omitted).
21. Powell v. McCormack, 395 U.S. 486, 496 (1969).
22. Nike, 568 U.S. at 90–91 (quotations omitted).
23. Lewis v. Cont’l Bank Corp., 494 U.S. 472, 477 (1990). See also Burke v. Barnes, 479 U.S. 361, 363 (1987) (“Article III of the Constitution requires that there be a live case or controversy at the time that a federal court decides the case; it is not enough that there may have been a live case or controversy when the case was decided by the court whose judgment we are reviewing.”).
24. See, e.g., DeFunis v. Odegaard, 416 U.S. 312, 314–15, 317 (1974) (holding that a lawsuit by a student who challenged a law school’s admissions policy as in violation of the Equal Protection Clause—and who had been admitted to the school after Justice William O. Douglas stayed, pending disposition in the U.S. Supreme Court, a judgment by the state supreme court reversing a ruling by the state trial court in the student’s favor—was moot when, at the time the case was eventually argued at the Court, the student was already in his final year at the school and “will receive his diploma regardless of any decision this Court might reach on the merits of this case”).
25. Nike, 568 U.S. at 91.
26. See, e.g., Fed. Election Comm’n v. Wisconsin Right To Life, Inc., 551 U.S. 449, 462 (2007) (ruling that a First Amendment as-applied challenge to a federal law prohibiting corporate electioneering communications during periods preceding federal elections was not mooted by passing of election cycle but instead “fit comfortably within the established exception to mootness for disputes capable of repetition, yet evading review,” and explaining that “[t]he exception applies where (1) the challenged action is in its duration too short to be fully litigated prior to cessation or expiration, and (2) there is a reasonable expectation that the same complaining party will be subject to the same action again”) (quotation omitted); Roe v. Wade, 410 U.S. 113, 125 (1973), overruled by Dobbs v. Jackson Women’s Health Org., 597 U.S. 215 (2022) (“Pregnancy provides a classic justification for a conclusion of nonmootness. It truly could be ‘capable of repetition, yet evading review.’”).
27. See, e.g., Clapper v. Amnesty Int’l, 568 U.S. 398, 420 (2013) (“[T]he assumption that if respondents have no standing to sue, no one would have standing, is not a reason to find standing.”) (quoting Valley Forge Christian Coll. v. Ams. United for Separation of Church and State, Inc., 454 U.S. 464, 489 (1982)).
28. See, e.g., Vikram David Amar & Evan H. Caminker, The Basis for Election Exceptionalism in Justiciability and Related Doctrines: “Constitutional Compensation” in Light of Purcell, 2024 U. Ill. L. Rev. 1451, 1466–76 (2024).
29. See Lawlor v. Nation Screen Serv. Corp., 349 U.S. 322, 327 (1955) (noting that judgment dismissing “the previous suit ‘with prejudice’ bars a later suit on the same cause of action”); Arthur R. Miller, Voluntary Dismissal—Effect of Dismissal, in Fed. Prac. & Proc. Civ. § 2367 (Charles Alan Wright & Arthur R. Miller eds., 4th ed. 2025) (“[A] dismissal with prejudice, whether by judicial order or stipulation is final, appealable, and unless the court has made some other provision, is subject to the general rules of preclusion—res judicata and collateral estoppel—and is effective not only on the immediate parties to the action but also on their privies.”).
30. Hecox v. Little, No. 1:20-CV-00184-DCN, 2025 WL 2917023, at *4–6 (D. Idaho Oct. 14, 2025).
31. Id. at *3 (emphasis in original) (internal citations omitted).
32. Id.
33. Id.
34. Id. at *4.
35. Id. at *5.
36. The district court did, in a footnote, mention the mootness issue, but found, speciously and circularly, that the court lacked the power to consider the mootness question because the Notice of Voluntary Dismissal was itself not properly before the court. See Hecox, 2025 WL 2917023, at *6 n.11.
37. Id. at *5.
38. 484 U.S. 193 (1988).
39. Id. at 204–05.
40. See id. at 200.
41. Id. at 200–01 (footnote omitted) (citation omitted).
42. Id. at 200 n.4 (emphasis in original).
43. Webster v. Reprod. Health Servs., 492 U.S. 490, 512 (1989).
44. Cf. Arizonans for Off. Eng. v. Arizona 520 U.S. 43, 75 (1997) (noting that “vacatur down the line [including at the district court] is the equitable solution” to prevent district court’s actions from allowing plaintiff to benefit from a now-moot case).
45. United States v. Munsingwear, Inc., 340 U.S. 36 (1950).
46. Id. at 39. Ironically, in Munsingwear itself vacatur was not ordered because of the unique circumstances of the case. See id. at 40–41.
47. Deakins, 484 U.S. at 200.
48. Munsingwear, 340 U.S. at 41.
49. See, e.g., Edward Cooper, 13 Wright & Miller’s Federal Practice and Procedure § 4433 (3d ed.).
50. 513 U.S. 18 (1994).
51. See id. at 29.
52. Id. at 25.
53. Id. at 23 (emphasis added).
54. Petitioners’ Response to Suggestion of Mootness at 11, Little v. Hecox, No. 24-38, U.S. (Sept. 26, 2025), 2025 WL 2831554.
55. 529 U.S. 277 (2000).
56. See id. at 287–88.
57. See id. at 283, 289.
58. Id. at 289.
59. Id.
60. Id. at 305 (Scalia, J., concurring).
61. See id. (“[T]he short of the matter is that we have no power to suspend the fundamental precepts that federal courts are limited by the case-or-controversy requirement.”) (quotation omitted).
62. 601 U.S. 1 (2023).
63. Id. at 3.
64. Id. at 2–3.
65. Id. at 3–4.
66. Id. at 4.
67. Id. at 5.
68. Id.
69. Id.
70. Id. at 9 (Thomas, J., concurring).
71. Id. at 10.
72. Id. at 8 (“Indeed, as the majority and Laufer herself acknowledge, we have the discretion to determine either ‘threshold groun[d] for denying audience to a case on the merits.’”) (emphasis added) (citation omitted).
73. Compare Craig v. Boren, 429 U.S. 190, 194 (1976) (expressing a desire to avoid “repetitive and time-consuming litigation” when federal judicial resources have already been expended in a case). It is important that the Court took account of this concern in the context of prudential, and not Article III, standing.
74. At the end of its order granting the defendants’ motion to strike, the district court in Hecox tipped its hand as to why it would not let Hecox abandon her claim: “Idaho has secured a writ of certiorari. It has a fair right to have its arguments heard and adjudicated once and for all.” Hecox v. Little, No. 1:20-CV-00184-DCN, 2025 WL 2917023, at *6 (D. Idaho Oct. 14, 2025). But that just isn’t how a grant of certiorari works. As we explained above, Article III requirements continue to apply after certiorari is granted. As frustrating as it might seem, there is no entitlement to a hearing and final resolution that displaces those requirements.
75. Of course, federal courts do have power (under Rule 11 and also inherently) to respond to what they conclude is inappropriate litigation conduct, but holding on to and resolving the merits of a case that is factually moot under Article III, in the sense that plaintiff has formally abandoned and cannot revive her claims, would never be an appropriate sanction.
76. See Order List (607 U.S.) 1 (Oct. 20, 2025), https://www.supremecourt.gov/orders/courtorders/102025zor_19m2.pdf [https://perma.cc/SC6X-LG37].
77. West Virginia v. B.P.J., No. 24-43, 2025 WL 1829164 (U.S. July 3, 2025) (mem.) (granting cert. to 98 F.4th 982 (4th Cir. 2024)).
78. See B.P.J. v. W. Va. State Bd. of Educ., 649 F. Supp. 3d 220, 223 (S.D. W. Va. 2023).
79. Id. at 233.
80. See B.P.J. by Jackson v. W. Va. State Bd. of Educ., 98 F.4th 542, 562, 565 (4th Cir. 2024).
81. There are possible paths to resolution of the equal protection issue. For the state petitioners to prevail in B.P.J, they will need to defeat both the Title IX and equal protection claims. If the Court rules for the petitioners on the Title IX claim, it will necessarily confront the equal protection issue which it could decide on the merits if it concludes that no additional development of the record or other proceedings in the lower courts are first needed. Even if the Court finds in favor of the respondent on the Title IX claim, it might still reach the equal protection claim if it concludes that the statutory and constitutional standards are the same and the principle of constitutional avoidance, see Ashwander v. Tenn. Valley Auth, 297 U.S. 288, 347 (1936) (Brandeis, J., concurring) (“The Court will not pass upon a constitutional question although properly presented by the record, if there is also some other ground upon which the case may be disposed of”), does not counsel against resolution of the constitutional issue. And we do note, of course, that the equal protection issues raised in B.PJ. and Hecox are not identical.
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