ment," Cleburne, supra, at 440. For example, the Court has held that statutory rape laws that criminalize sexual intercourse with a woman under the age of 18 years, but place no similar liability on partners of underage men, are grounded in the very real distinction that "young men and young women are not similarly situated with respect to the problems and the risks of sexual intercourse." Michael M. v. Superior Court, Sonoma Cty., 450 U.S. 464, 471 (1981) (plurality opnion). The plurality reasoned that "[o]nly women may become pregnant, and they suffer disproportionately the profound physical, emotional, and psychological consequences of sexual activity." Ibid. In other contexts, however, the Court has found that classifications based on gender are "arbitrary," Reed, supra, at 76, and based on "outmoded notions of the relative capabilities of men and women," Cleburne, supra, at 441, as when a State provides that a man must always be preferred to an equally qualified woman when both seek to administer the estate of a deceased party, see Reed, supra, at 76–77.
Finally, so-called rational-basis review applies to classifications based on "distinguishing characteristics relevant to interests the State has the authority to implement." Cleburne, supra, at 441. We have long recognized that "the equal protection of the laws must coexist with the practical necessity that most legislation classifies for one purpose or another, with resulting disadvantages to various groups or persons." Romer v. Evans, 517 U.S. 620, 631 (1996). As a result, in rational-basis cases, where the court does not view the classification at issue as "inherently suspect," Adarand Constructors, Inc. v. Peña, 515 U.S. 200, 218 (1995) (internal quotation marks omitted), "the courts have been very reluctant, as they should be in our federal system and with our respect for the separation of powers, to closely scrutinize legislative choices as to whether, how, and to what extent those interests should
