I commented here that:
I think the issue of gay marriage is a proxy for a debate over social changes. I think what most so-cons really care about is the general failing state of marriage, and gay marriage is just the issue where they’ve decided to make a stand. And honestly I do not think most on the left really care about these issues, or even see them as positive developments (liberation from patriarchy!). You and others argue that gay marriage will actually strengthen the institution, and while I don’t doubt your sincerity, I think this argument is often advanced in bad faith.
Let me put it this way – I think anyone advancing your kind of argument should be required to state what positive legal/social/cultural steps they want to take to fight the rising tide of divorce, single motherhood, out-of-wedlock births, etc.
Here in Britain gays can form civil partnerships, which are basically marriages without the word marriage. But, just as in California, there is a legal challenge, from activists who want to redefine the terms. This is, in the true sense, political correctness, forcing a certain set of language on the population in the hope of gaining equal esteem for gay relationships as normal ones.
I’m generally hostile to that kind of quixotic project, but this one strikes me as relatively harmless. So if gay marriage activists are really serious about strengthening marriage not undermining it, I’ll support them if they give me something I want in return. For instance, I would happily support gay marriage if it came coupled with a reform of divorce laws to give fathers get equal rights of custody, eliminate divorce theft and make pre-nuptials enforceable. Or it could be benefit reform, or eliminating no-fault divorce, or whatever else.
Of course, if you aren’t willing to do anything positive to strengthen marriage, then I must assume that your argument that gay marriage will strengthen the institution is insincere.