He was recently interviewed by the Economist, about six Big Questions. The interview is well worth reading overall, but I am (predictably) going to focus on one of his answers:
Question: You've argued that the state of California ought to get itself out of the business of overseeing marriage. But at the same time, you maintain that "the state has an interest in officially recognising some relationships just to ensure that society is well organised". By what sort of standards should the state decide which relationships to sanction?Now, I hadn't even considered that the Court would find this way: that if Prop8 applied, NO ONE gets the title "marriage" for their state-sanctioned union. It's the most sensible answer to separate church from state in this case, but ---oh my. I'd love to see the Other Side hoist on this petard. Aw, well. It'll never happen.
Mr Kmiec: As I see it the state has an obligation to observe both equality and religious freedom. It cannot do both if it disavows its finding that sexual orientation is a suspect classification or presumes to perform an act that should be reserved for religious congregations–namely, marry two people in the sight of God in accordance with whatever doctrinal teaching the couple’s voluntarily-chosen church, synagogue, mosque, or temple observes.
This incompatibility became even more obvious when the people of California passed proposition 8, restricting marriage to opposite-sex couples. In a case pending before the California Supreme Court, it was conceded by the measure's advocate that it was not aimed at depriving gay and lesbian citizens of equal rights and benefits, which the state Assembly had already provided to them in statute. That concession seemed unavoidable, especially given the status of sexual orientation as suspect. So the effect of proposition 8–assuming it is upheld as a valid amendment–is solely to make the nomenclature of marriage available only to one class of citizens–heterosexuals. Since the state has the primary obligation of equality for all, the effect of the proposition is to direct the state to issue a license by a name other than marriage to all couples–gay or straight–who apply. The concept of marriage, of course, is then fully remitted to religious bodies who can indulge same-sex marriage within their respective religious communities or not in accord with the religion’s doctrine.