With a one-sentence order last week, the Supreme Court dashed hopes of a big transgender-rights decision this term. The Court was supposed to review the case of Gavin Grimm, a transgender teen-age boy who sued the Gloucester County School Board for the right to use the boys’ bathroom and won, in the Fourth Circuit. But the basis of the Fourth Circuit’s decision was the Obama Administration’s view that Title IX, the 1972 law that prohibits schools that receive federal funding from discriminating “on the basis of sex,” requires schools to treat transgender students in a way consistent with their gender identity. Last month, the Trump Administration retracted that position. Both Grimm and the school board urged the Supreme Court to review the case as planned, arguing that the government’s shift made it no less urgent for the Court to declare Title IX’s meaning. But the Supreme Court decided to vacate the lower court’s decision and send the case back for reconsideration. Grimm’s victory in the lower court was tethered to the Obama guidance, and disappeared along with it.

That leaves the Fourth Circuit to directly confront what Title IX means for schools and transgender students. Given that a 1975 federal regulation implementing Title IX permits “separate toilet, locker room, and shower facilities on the basis of sex,” can schools keep transgender students out of facilities that correspond to their gender identity? The losing party in that decision will surely ask the Supreme Court for review, but, in the meantime, the transgender-rights fight resumes in lower courts and states, in a landscape greatly altered by the government’s change of position. When a divisive social issue plays out in courts, legislatures, and communities, the process is normally messy, and filled with pain and struggle for the people involved—in this instance, schoolchildren. But the combination of the sharply conflicting Obama and Trump guidances, the Supreme Court’s refusal to review a case it had already agreed to hear, and the elimination of an important lower-court transgender win has escalated the confusion to an unusual degree.

The Trump Administration’s guidance does not require schools to bar transgender students from gender-corresponding bathrooms. But one state has done so, and gone even further. Last March, North Carolina passed a law mandating that all public schools and public agencies “must require” that bathrooms and changing facilities be used based on a person’s sex on his or her birth certificate. The Obama Administration issued its guidance on transgender students in May, and Obama’s Justice Department sued North Carolina that month, claiming that the state had violated federal civil-rights laws. But that suit looks as though it will soon be abandoned by Trump’s Justice Department, which indicated in a motion this month that it needs time to rethink its position on the North Carolina law. If the suit is deserted, any state could follow North Carolina’s lead without facing repercussions from the federal government.

No appellate court has considered the question that is before the Fourth Circuit in Grimm’s case—what “sex” means for transgender students in the phrase “on the basis of sex” in Title IX and its regulations. But in a lawsuit filed by thirteen states challenging Obama’s transgender guidance, a Texas federal district court stated last fall that “sex” unambiguously means sex assigned at birth, not gender identity. That court blocked enforcement of the guidance nationwide while the suit was ongoing, and the Obama Administration appealed in the Fifth Circuit. But after the Trump Administration announced that it would not defend the Obama guidance and dropped the appeal, the states agreed to drop the suit altogether.

While the federal government abandons its positions defending transgender bathroom access, a challenge to North Carolina’s bathroom law, brought on behalf of transgender North Carolinians by the American Civil Liberties Union, Lambda Legal, and the firm of Jenner & Block, will proceed in federal district court. Last summer, a North Carolina federal district court temporarily blocked enforcement of the law against student plaintiffs, adopting the rationale of Grimm’s Fourth Circuit case, which deferred to Obama’s Title IX guidance. Now that the Supreme Court has vacated the Fourth Circuit case, that injunction could be challenged by North Carolina, too. The district court also said that the plaintiffs were unlikely to succeed in their constitutional claim: that the North Carolina law violated the Equal Protection Clause of the Fourteenth Amendment. The transgender plaintiffs’ appeal of that decision will be argued in the Fourth Circuit, in May.

Meanwhile, three transgender high-school students in suburban Pittsburgh (including the sister of Jackie Evancho, who sang at President Trump’s Inauguration) brought a suit challenging their school district’s policy excluding transgender students from gender-corresponding bathrooms. Last month, a Pennsylvania federal district court temporarily enjoined enforcement of the policy, saying that the students were likely to succeed at trial on their constitutional equal-protection claim. But the new Trump guidance caused the court also to say that the students’ Title IX claim was unlikely to succeed. This win on equal protection, but not on Title IX, represents the reverse of the outcomes of the North Carolina case, indicating that, as the Title IX arguments grow weaker without the federal government’s supporting interpretation, constitutional arguments may well rise up to accomplish the same protection for transgender people.

A majority of Americans do not support excluding transgender people from bathrooms consistent with their gender identities, and Republican leaders are less likely now than they were a year ago to view division on the bathroom issue as helpful to their party. North Carolina has borne significant costs for its bathroom law, including the N.B.A. and N.C.A.A. pulling events out of the state and PayPal cancelling expansion plans. The former Republican Governor Pat McCrory is widely thought to have lost his reëlection bid to a Democrat in part because of his association with the bathroom law. Texas and Arkansas are currently considering bathroom bills similar to North Carolina’s, but they are unlikely to pass, facing strong opposition from both civil-rights activists and pragmatic protectors of the states’ economic interests. Corporations such as Google, Amazon, American Airlines, Microsoft, Intel, and Hilton have opposed the proposed Texas bathroom bill, as have the N.F.L. and the N.B.A.

The transgender-rights movement is commonly seen as an extension of the movements for gay rights, women’s rights, and the rights of racial minorities. Many of the legal arguments on behalf of those groups relied heavily on the idea that we were dealing with “immutable” characteristics of human beings. In a 1973 sex-discrimination case (litigated by Ruth Bader Ginsburg, who was then a lawyer for the A.C.L.U.), Justice William Brennan wrote that “sex, like race, is an immutable characteristic determined solely by the accident of birth.” The concept that homosexuality is inborn and unchangeable also became an important part of the gay-rights movement—with the questionable implication that if one’s sexuality involved choice, then discrimination based on it might make more sense.

The transgender-rights fight has the potential to reveal the inadequacy of “immutability” as a concept supporting identity and non-discrimination, because it forces us to consider a person’s transition from one construction of identity to another. But while transgender identity might highlight the fluidity of gender, we have also seen arguments supporting transgender rights that insist that gender identity is innate and fixed. Anxiety that transgender rights may stall if being transgender does not fit the immutability model may create incentives to view gender itself as natural, inborn, and unchangeable.

Questions about what constitutes sex discrimination against transgender people will be alive long after we have answers on bathroom access. They have many dimensions, including sex-segregated sports and living quarters. And they implicate the deeper issues of what sex and gender are, and what is achieved by organizing aspects of our society according to those categories. In the coming years, perhaps the current upheaval in schools and other social institutions will calm down somewhat, as more cases make their way through the courts and we can discern a pattern of decisions, whether based on Title IX, equal protection, or other legal grounds. At the very least, the developing social consensus will be clearer—and then it will be time for the Supreme Court to tell us the contemporary legal meanings of sex and gender.