It's been a long night of hot chocolate, vodka, and Michigan-style metanormative theory, and now I have the pleasure of talking to conservative philosophers about whether gays and lesbians should be allowed to marry. There's two big claims in Keith's post (Keith occasionally goes by AnalPhilosopher, but since I take the more anus-friendly side of this issue, that name may not fit him here). First, he says that this issue is a political loser for the Democratic Party. Second, he says that granting gays and lesbians the right to marry would be a significant change in our practices and there should be a heavy presumption against it.
On the first thing, let's look at some actual polling data, rather than using the >75% opposition number that the AnalPhilosopher pulled out of his ass (sorry). Skip down past the lawsuit stuff to see the gay marriage numbers. Usually, you get 30+% support for full-fledged marriage and ~60% opposition with 5-10% undecided, when those are the only options offered. While a slight majority opposes civil unions, the civil-union + full-fledged marriage disjunction actually wins a majority when both options are offered. My guess is that the next Democratic nominee will be a mere civil unions guy*. I accept that there'll be a slight majority opposing this view -- something like 55-45. It's not what we'd like, but this talk of a 'liberal death wish' is radically overstated. And oddly enough, on some questions independents seem to support gay people's right to marry more than Democrats do!
But now I get to my favorite part. According to every poll that breaks things down by age groups, the 18-29 age bracket is by far the most pro-gay, and the 65+ folks are the most anti-gay. (There are only older polls on this, so click on the second poll link). On most questions the young people support gays at more than triple the rate of old people. Sure, this is going to be a tough issue in the short-term for Democrats. But eventually the old folks will cease to be physically located, the kids will grow up, and Democratic fortunes will grow with them. In terms of sheer political strategy, supporting gay people's right to marry is an investment that's going to pay off huge for us. Twenty years from now, we'll have a clear majority and you guys will be trying to figure out what to do with a losing position that costs you more every year. Fifty years from now, the right to marry will be regarded like integration is today. All our grandchildren will see the conservatives like we now see George Wallace and the old segregationists, and acknowledge that the liberals were the heroes of the tale. So it ever has been between us; so it ever shall be.
This assumes, of course, that Keith is wrong on the second question. If expanding the right to marry has the unexpected consequence of destroying essential social structures and causing serious misery, my fifty year scenario goes out the window. But that won't happen. Remember, the proposal we liberals want makes absolutely no changes to heterosexual marriage. If some wacky theory motivated us to propose that every marriage be required to involve 3 persons and a duck, you guys would be right to complain about us destroying useful old institutions willy-nilly. Big presumption against! But we're not changing the basic structure of any existing social institution (except maybe antigay prejudice) -- we're just copying an institution and allowing a couple more people to use the copy. People currently covered by heterosexual marriage will hardly notice the difference, while those newly allowed to marry will be much the better for it. The presumption against allowing gay people to marry should be small because the fundamental and wonderful institution of heterosexual marriage is unaffected by it.
If you're going to object that there's something incoherent about the idea of two women getting married, my rebuttal and Justin's addition to it have already been posted. So Keith, I urge you to drop the scare quotes around the latter term in 'homosexual "marriage"'. And while you're at it, we're called the 'Democratic Party' and not the 'Democrat Party'.
On the whole, I expect that this expansion of the right to marry won't be nearly as far-reaching a social change as integration. Many fewer people are directly affected, and the indirect effects are small. So if you fear radical social changes, there's really not much here to be afraid of and only a tiny presumption against should apply. At the very least, you ought to support civil unions. They're a nice incremental measure, if that's how you like it. When you see after a decade or so of civil unions that we aren't falling into barbarism, you'll be ready to go the rest of the way.
*My prediction is that it'll be John Edwards, who is a mere civil unions guy. There may be a lot of wishful thinking behind this prediction, though. I briefly volunteered for Edwards during the primaries and I plan to do so again in '08.