Is gay marriage unstoppable?

Unlike the recent decisions, Justice Kennedy’s Windsor opinion was a narrowly tailored document with a two-part logic. First he observed that marriage is a matter for the states, some of which had extended it to include same-sex couples. Second he wrote, “interference with the equal dignity of same-sex marriages, a dignity conferred by the States in the exercise of their sovereign power, was more than an incidental effect of the federal statute. It was its essence.”

I’ve italicized that phrase for a reason. Notice that Justice Kennedy did not say same-sex marriage is a fundamental right or that DOMA violated the equal protection clause on its own terms. Rather, the state of New York had conferred the “dignity” of marriage on its gay and lesbian couples—and Congress had taken it away. Concluding that DOMA violated the Fifth Amendment’s due process clause, the Windsor opinion held that “no legitimate purpose overcomes the purpose and effect to disparage and to injure those whom the State, by its marriage laws, sought to protect in personhood and dignity.”

That is a jurisprudentially conservative opinion, even if it led to a socially liberal result. Congress cannot treat unequally those whom a state has chosen to treat equally. Most of the last year’s marriage opinions have been far broader.