The drama of Supreme Court cases usually peaks in the days leading up to the Court’s decision, as the media prepares to capture the smiling faces of the victors as they emerge triumphant on the courthouse steps. But sometimes, the real drama is in the details. The practice of law, particularly at the Supreme Court level, isn’t all grand orations and groundbreaking decisions. It’s made up of incremental steps, each of which is essential to the machine of legal progress. In the case of Gloucester County School Board v. G.G., one of those seemingly innocuous incremental steps has just thrown a major wrench into the machine.

Yesterday, the Supreme Court extended a deadline, and with that one move, everything may have changed. First, a refresher on the case at bar. Gavin Grimm is a 17 year-old transgender boy in rural Virginia who sued his local school district over a policy requiring him to use the girls’ bathroom. The crux of Gavin’s claim was that a rule mandating the use of bathrooms that correspond with “biological gender” violates his civil rights, and the civil rights of other transgender students. As my LawNewz.com colleague David Bixenspan explained a few months ago, the principal at Gavin’s school changed the restrictive policy, but then instituted a rule requiring Gavin to use a single-stall unisex restroom.

Lawsuits followed, and in October, the Supreme Court granted certiorari to review the case. A central issue in the litigation is whether Title IX (the federal law prohibiting gender discrimination) requires that transgender students be permitted to use bathrooms consistent with their gender identity. It’s a pretty big deal, and it could have impact far beyond bathrooms. If SCOTUS rules that it is “discriminatory” to require specific bathroom use, transgender people will realize a major step forward in the fight for the legitimization of the concept of gender identity. So much about this case, as with all cases, hinges on the specific arguments advanced by the parties actually litigating. It is not enough for a court to rule about what’s “fair” in a general sense; courts must rather determine what is “legal” by interpreting statutes and ruling on questions actually raised by litigants.

Originally, the “merits brief” (the brief in which the Gloucester County School Board would lay out its arguments) for Gloucester County School Board v. G.G. was due on December 12. Gavin Grimm’s reply brief would have been due 30 days later, on January 11. Yesterday, though, the Supreme Court extended the timeline, and changed the due-date for the school board’s brief to January 3, with Gavin Grimm’s brief following on February 23. The change is not a simple month-long extension that conveniently gives litigants more time to attend holiday parties. Rather, it is a change that has the potential to change the entire shape of this litigation.

Because this case relates to a legal interpretation of Title IX, Gavin Grimm’s arguments have centered around the current federal interpretation of Title IX. He won at the lower court level based on those arguments, all of which were based on the Obama-administration’s position on Title IX and gender discrimination.  The May, 2016 “Dear Colleague” letter penned by Catherine E. Lhamon, Assistant Secretary for Civil Rights U.S. Department of Education, and Vanita Gupta, Principal Deputy Assistant Attorney General for Civil Rights U.S. Department of Justice, the Obama Administration’s position on school district treatment of transgender students was clear:

“The Departments interpret Title IX to require that when a student or the student’s parent or guardian, as appropriate, notifies the school administration that the student will assert a gender identity that differs from previous representations or records, the school will begin treating the student consistent with the student’s gender identity. Under Title IX, there is no medical diagnosis or treatment requirement that students must meet as a prerequisite to being treated consistent with their gender students often are unable to obtain identification documents that reflect their gender identity.  Because transgender students often are unable to obtain identification documents that reflect their gender identity (e.g., due to restrictions imposed by state or local law in their place of birth or residence), requiring students to produce such identification documents in order to treat them consistent with their gender identity may violate Title IX when doing so has the practical effect of limiting or denying students equal access to an educational program or activity.”

That policy, and the fact that the federal government committed to protecting transgender students from gender-based discrimination, is central to Gavin Grimm’s case. But the change in brief due-dates means now, the incoming Trump Administration has the opportunity to change positions on this matter. The “Dear Colleague” letter could be rescinded, and the position could be materially altered – and that’s to say nothing of a ninth justice who may well be appointed before this case is decided. A change in federal position on Title IX and gender discrimination threatens to pull the rhetorical rug out from under Gavin Grimm. Such a change might result in a number of unfavorable outcomes – from an outright loss at the SCOTUS level to a punt back down to the lower court. Either way, what seems like a short extension could mean big trouble for the fight for transgender equality.