A divided U.S. Supreme Court overturned the federal law that defines marriage as a heterosexual union, saying it violates the rights of married gay couples by denying them government benefits.
The vote on the Defense of Marriage Act was 5-4. Justice Anthony Kennedy joined the four Democratic-appointed justices in the majority.
The law “places same-sex couples in an unstable position of being in a second-tier marriage,” Kennedy wrote for the court. “The differentiation demeans the couple, whose moral and sexual choices the Constitution protects, and whose relationship the state has sought to dignify.”
The court will act momentarily on a second gay-marriage case, involving California’s Proposition 8, which bars same-sex couples from marrying.
The historic cases, which marked the first time the high court had ever considered gay-marriage rights, reached the justices as the movement was showing unprecedented momentum. Twelve states and the District of Columbia have legalized same-sex marriage, six of them in the last year.
Joining Kennedy in the majority on the Defense of Marriage Act ruling were Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan.
Dissenting were Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel Alito.
“We have no power under the Constitution to invalidate this democratically adopted legislation,” Scalia wrote in dissent.