Yglesias has a suggestion for supporters of traditional marriage:
…if we want to bolster traditional marriage it seems to me that a much more reasonable measure than discrimination would be to say that you only get two divorces. After that, you can go about your business as you please, but no more spouses; you’re clearly not a person capable of making credible commitments.
While it’s question-begging to call opposition to gay marriage “discrimination,” that’s just the state of the discourse these days, so I’ll just say that I agree. Sociologically, this would be a much greater victory for marriage than maintaining whatever is left of the institution’s orientation towards complementary sexual union.