Page:Adams ex rel. Kasper v. School Board of St. Johns County, Florida (2020).pdf/62

 The majority’s other contention—that believing “one’s gender identity and expression should align with one’s birth sex” is an unconstitutional stereotype—fares no better. The Supreme Court has long grounded its sex-discrimination jurisprudence in reproductive biology. See, e.g., Nguyen, 533 U.S. at 73 (“The difference between men and women in relation to the birth process is a real one … .”); Geduldig, 417 U.S. at 496 n.20 (“[I]t is true that only women can become pregnant … .”); see also Virginia, 518 U.S. at 533 (“Physical differences between men and women, however, are enduring: [T]he two sexes are not fungible … .” (internal quotation marks omitted)). Indeed, the Court’s justification for giving heightened scrutiny to sex-based classifications makes sense only with reference to physiology.

In one of its foundational sex-discrimination decisions, the Court justified heightened scrutiny this way: “since sex … is an immutable characteristic determined solely by the accident of birth, the imposition of special disabilities upon the members of a particular sex because of their sex would seem to violate the basic concept of our system that legal burdens should bear some relationship to individual responsibility.” Frontiero v. Richardson, 411 U.S. 677, 686 (1973) (plurality opinion) (internal quotation marks omitted). In other words, the Court endorsed heightened scrutiny because laws “distributing benefits and burdens between the sexes in different ways very likely reflect outmoded notions of the