The Minnow didn't get shipwrecked on Marriage Island yesterday
I've always been in favor of civil unions myself, even back when that stance represented the leftward fringe of the marriage debate. Mutually consenting parties should not be prevented from entering into legal contracts for things like inheritance or hospital visitation rights. Companies that want to offer benefits to same-sex partnerships should face no legal obstacles; it's their call to make.
But we sailed right past that point a few years ago, because same-sex marriage advocates wouldn't settle for it. This very point was raised at the Supreme Court yesterday, as one of the Justices (I don't recall which one) pointed out that California already grants just about every imaginable benefit to same-sex couples, so Prop. 8 had very little practical effect; were its opponents really just insisting on having the word "marriage" as well?
That's my problem with the "get government out of marriage" strategy, which has understandable logical appeal to libertarians, and political appeal to Republican politicians who would rather step out of the marriage discussion. Completely disengaging the legal structure from marriage is far more difficult than conventional libertarian opinion would have it, particularly where children are involved. But leaving that aside, I simply don't think the same-sex marriage side would go for it. They don't want the government out of marriage.
And even though I'm in favor of preserving the traditional definition of marriage, I can easily see their point. They aren't going to settle for a largely rhetorical concession. They want more than the word "marriage"; they want its meaning. Marriage is not just a private agreement between two people - it's a bond society is obliged to respect. You don't get to ignore a marriage you disapprove of, although any number of disappointed parents and frustrated suitors have been tempted to try.
It wasn't more than a couple of weeks after the gay marriage law passed in Washington State that we heard of the first lawsuit against a bakery that refused to make a same-sex wedding cake. That's going to expand into the religious sphere, since as you noted marriage has a unique status as both legal artifact and religious sacrament. Mark Steyn recently made this comment about the state of gay marriage in Canada (in the course of noting the Canadian government's remarkable tolerance of certain groups that aren't very tolerant of gay existence):
In Canada, gay marriage is legal coast to coast; "gay-straight alliance" groups are mandated in every school in Ontario; Catholic educational institutions are obliged to let students bring their same-sex partners to the prom; publicly funded "Pride" parades are obligatory in not just the louche metropolitan fleshpots but remote small towns; gay arts festivals are enthusiastically sponsored by the Royal Bank of Canada, Air Canada, and every other important corporation. As societal approval goes, that's not bad for a demographic that represents 2 percent of the population.
That doesn't sound much like "decoupling the government from marriage."
I've always thought the tendency to pretend we're starting with a blank slate and writing the rules of society is silly. To extend that Gilligan's Island metaphor, the Minnow did not shipwreck on Marriage Island yesterday. The gay-marriage side of the debate would say that just because a tradition is old doesn't make it right, invariably referencing slavery to make their point. Fair enough, but I would respond by noting that old traditions also are not arbitrary customs mindless people follow on autopilot for centuries. There are reasons - sometimes very logical reasons that stand up just fine without leaning on religious authority - for enduring, nearly universal traditions like marriage.
Maybe the defenders of traditional marriage should have focused more strongly on those reasons, but I'm not sure the younger generation would listen. The value accorded to marriage in our society decayed long before anyone started talking about waiving the man-and-woman requirements. It won't be easy to recover that value; it becomes immeasurably more difficult if "marriage" can now be any random couple, or group, of people.
But in any event, and to trot out the Gilligan's Island analysis one more time, at this point it's not Thurston Howell III and Lovey who will most strongly resist the notion of keeping government out of marriage.