2 SESSIONS v. MORALES-SANTANA Syllabus Santana later moved to reopen the proceedings, asserting that the Government’s refusal to recognize that he derived citizenship from his U. S.-citizen father violated the Constitution’s equal protection guarantee. The Board of Immigration Appeals denied the motion, but the Second Circuit reversed. Relying on this Court’s post-1970 construction of the equal protection principle as it bears on genderbased classifications, the court held unconstitutional the differential treatment of unwed mothers and fathers. To cure this infirmity, the Court of Appeals held that Morales-Santana derived citizenship through his father, just as he would were his mother the U. S. citizen. Held: 1. The gender line Congress drew is incompatible with the Fifth Amendment’s requirement that the Government accord to all persons “the equal protection of the laws.” Pp. 6–23. (a) Morales-Santana satisfies the requirements for third-party standing in seeking to vindicate his father’s right to equal protection. José Morales’ ability to pass citizenship to his son easily satisfies the requirement that the third party have a “ ‘close’ relationship with the person who possesses the right.” Kowalski v. Tesmer, 543 U. S. 125, 130. And José’s death many years before the current controversy arose is “a ‘hindrance’ to [José’s] ability to protect his own interests.” Ibid. Pp. 6–7. (b) Sections 1401 and 1409 date from an era when the Nation’s lawbooks were rife with overbroad generalizations about the way men and women are. Today, such laws receive the heightened scru­ tiny that now attends “all gender-based classifications,” J. E. B. v. Alabama ex rel. T. B., 511 U. S. 127, 136, including laws granting or denying benefits “on the basis of the sex of the qualifying parent,” Califano v. Westcott, 443 U. S. 76, 84. Prescribing one rule for moth­ ers, another for fathers, §1409 is of the same genre as the classifica­ tions declared unconstitutional in Westcott; Reed v. Reed, 404 U. S. 71, 74, 76–77; Frontiero v. Richardson, 411 U. S. 677, 688–691; Weinberger v. Wiesenfeld, 420 U. S. 636, 648–653; and Califano v. Goldfarb, 430 U. S. 199, 206–207. A successful defense therefore requires an “ ‘exceedingly persuasive justification.’ ” United States v. Virginia, 518 U. S. 515, 531. Pp. 7–9. (c) The Government must show, at least, that its gender-based “ ‘classification serves “important governmental objectives and that the discriminatory means employed” are “substantially related to [achieving] those objectives.” ’ ” Virginia, 518 U. S., at 533. The clas­ sification must serve an important governmental interest today, for “new insights and societal understandings can reveal unjustified ine­ quality . . . that once passed unnoticed and unchallenged.” Obergefell v. Hodges, 576 U. S. ___, ___. Pp. 9–14.