570 U.S. 744 (2013)
Windsor v. United States is a pivotal case in the realm of constitutional law and civil rights, addressing the legality of the Defense of Marriage Act (DOMA), which defined marriage federally as a union exclusively between one man and one woman.
Does Section 3 of the Defense of Marriage Act, which defines 'marriage' and 'spouse' as excluding same-sex partners, violate the Fifth Amendment's guarantee of equal protection under the law?
The Fifth Amendment, through principles of equal protection, prohibits the federal government from enacting laws that discriminate unjustifiably against a particular class of individuals.
The Supreme Court held that Section 3 of DOMA violated the Fifth Amendment by depriving legally married same-sex couples of the equal protection of the laws accorded to opposite-sex couples.
Windsor v. United States holds significant implications for constitutional law, notably in the area of equal protection and federalism. It reinforced the principle that classifications based on sexual orientation warrant equal protection scrutiny and paved the way for further advances in marriage equality, culminating in Obergefell v. Hodges (2015), which extended marriage rights to same-sex couples nationwide. For law students, Windsor is critical for understanding the interplay between federal and state powers in defining marital relationships, as well as the evolving judicial interpretation of equality and civil rights.