West Virginia v. B. P. J.

Majority reasoning

The majority held that the word "sex" in Title IX and its implementing regulations, as understood when enacted in the early 1970s, means biological sex — and that those regulations expressly permit schools to maintain separate teams for each sex, precisely because of the inherent physical differences between biological males and females. The Court reasoned that limiting girls' and women's teams to biological females is "reasonable" under the Javits Amendment because it addresses real safety risks and competitive fairness concerns, and that 27 states, the NCAA, the U.S. Olympic and Paralympic Committee, and the International Olympic Committee have all drawn the same line. On the Equal Protection Clause, the Court applied intermediate scrutiny — the legal test (requiring a "substantial relationship" to an "important" government interest) used for laws that classify people by sex — and found that the states' interests in safety and competitive fairness are important and that limiting female teams to biological females is substantially related to those interests. The Court further held that states are not constitutionally required to conduct athlete-by-athlete assessments of physical capabilities, because intermediate scrutiny judges a classification by its relationship to the overall problem the government seeks to solve, not by whether it works perfectly in every individual case. Finally, the Court deferred to legislatures on the unsettled medical and scientific question of whether transgender girls who take puberty blockers or hormones retain physical advantages, reasoning that courts should be cautious about overriding legislative judgments in areas of genuine scientific uncertainty.

Dissent reasoning

The dissent, written by Justice Sotomayor and joined by Justices Kagan and Jackson, agreed that B.P.J.'s Title IX claim fails but argued the majority got the Equal Protection analysis wrong by cutting off the case before the facts were fully developed. The dissent argued that under the Court's own precedents — particularly Caban v. Mohammed and United States v. Virginia — a sex-based classification can violate equal protection when it sweeps in a discrete, identifiable subclass of people as to whom the state's interests are not actually furthered, and that this factual question had never been resolved by the lower courts. The dissent contended that B.P.J. presented a genuine, unresolved factual dispute: whether transgender girls who have never experienced a male puberty and who receive gender-affirming hormonal treatment actually retain any athletic advantage over biological females — and that this dispute was potentially outcome-determinative under proper heightened scrutiny. The dissent further argued that the majority improperly borrowed its deference-to-legislatures reasoning from cases applying rational basis review (the more lenient legal test used for ordinary laws), not the stricter "heightened scrutiny" standard that sex classifications require, and that the majority cited scientific studies not in the record. In the dissent's view, the proper course was to send the case back to the lower courts to resolve the factual dispute first, rather than deciding the constitutional question without a complete evidentiary record.