It’s springtime, and marriage is in the air. Major constitutional battles about legal recognition for the marriage rights of same-sex couples are wending their way through the federal courts. Two couples are challenging California’s marriage restrictions; several other couples, in a series of lawsuits around the country, are challenging the federal government’s Defense of Marriage Act (DOMA) for denying federal benefits to couples validly married under state law in states such as Massachusetts (which issues marriage licenses to gay couples) and New York (which recognizes same-sex marriages performed elsewhere).

Along the way, supporters of marriage equality have commonly invoked the Supreme Court’s 1967 decision in the aptly captioned Loving v. Virginia. There, the Court held that Virginia’s criminalization of interracial marriage violated two provisions of the Fourteenth Amendment: the equal protection clause, because Virginia’s law could be explained only as the product of illegitimate racial prejudice, and the liberty element of the due process clause, because Virginia denied Mildred and Richard Loving “the freedom to marry” that “has long been recognized as one of the vital personal rights essential to the orderly pursuit of happiness by free men.” Restricting marriage to opposite-sex couples likewise relies on prejudiced, or empirically dubious, propositions about gay people and their families, and denies them a status that confers dignity and a bundle of tangible entitlements central to modern life.