Current wisdom suggests that if right-wingers like marriage so much it’s really stupid of them to object to “gay marriage.” After all, shouldn’t long-term commitments be encouraged by respect, ceremony, and the web of custom and observance that has gathered around marriage? Isn’t that sort of thing the essence of social conservatism?
No doubt it would be if social conservatism were a sort of social engineering with no use for human nature and a firm conviction that it can make anything so by pronouncing the proper words. Custom and culture do not hang in the air, however, without reference to nature. The reason marriage is marriage is that it has a natural function, the union of a man and woman for procreation and the rearing of children. That is a function necessary to society, so people support it. It immoveably demands long term loyal cooperation, so the habits and attitudes that developed in connection with it promote those things.
Take the function away, which is what the expansion of marriage to same-sex relationships would do, and there’s no reason why the the same habits and attitudes would remain. The standard would become one of personal fulfillment, which is no standard at all. So “gay marriage” would in the end be no benefit to homosexuals who see it as a check to hedonism. Rather, it would complete the process that has been turning marriage itself into just another expression of the universal right of self-expression.