from the judge's opinion:
"The Policy clearly implicates the Equal Protection Clause. It treats M.A.B. differently from the rest of the High School's students. While the rest of M.A.B.'s peers may use the locker room that aligns with their gender identity, M.A.B. may not.
"Instead, Defendants discipline M.A.B. if he uses such a locker room—the boys' locker room. As a matter of fact, his physical education teacher penalized his grade when M.A.B. did not change his clothes because he did not want to deal with the "stigma and impracticality" of changing in the designated restrooms. Also, M.A.B. had to disclose his transgender status to substitute teachers to avoid disciplinary action for being late to class after changing in those distant restrooms.
"None of these events would occur if the Policy permitted M.A.B. to change in the locker room that aligns with his gender identity, like the rest of the students at the High School. Thus, the Policy implicates the Equal Protection Clause."
Here's a link to full text of the Judge's Opinion and Memorandum Order (40 pages):
https://freestate-justice.org/wp-content/uploads/2018/03/MAB-2018.03.12-Memoradum-Opinion-Denying-Motion-to-Dismiss-and-PI.pdfThe case is
M.A.B. v. Board of Education of Talbot County, U.S. District Court for the District of Maryland, March 12, 2018.