Which is why I find the whole "marriage is between one man and one woman" thing so funny. There are plain language efforts out there on various ballots and through various lawsuits to define it so. For example, Washington state's Initiative 1192, which says:
Sec. 1. This act reaffirms the definition of marriage as being between one man and one woman.
(Sorry, no link. I see no reason to reward the ridiculous bigotry of 1192's backers with a bit of my blog traffic. It's easily Googled if you want to look at the entire text yourself. There's not much more to it.)
Ok, that's fine. Unambiguous. Biblical, even, assuming you ignore most of the Old Testament in your definition of Biblical marriage. I'm pretty sure only the gay-hating parts of the Old Testament count for most American Christians anyway, so the whole King Solomon's wives things and the David-and-Bathsheeba thing and the not bearing false witness thing and so on don't really apply as the literal and inviolate word of God.
Except what do conservatives do about intersexed people? Or transgendered people? If a cisgendered man and woman are married, then one of them transitioned, is the marriage rendered invalid? Are intersexed people not permitted to marry at all?
Oops. Nuance. Conservatives don't do nuance. Much easier to pretend the edge cases don't exist, or don't apply.
Even more interestingly, insofar as I know, in the United States there's not a strict legal definition of gender. Pretty much for the reasons cited above. So I'm curious what happens if one member of a same-sex couple simply declares themselves of the other gender. That fails what some conservatives would call obvious common sense tests, but law isn't about the obvious. Or common sense.
Oops. Nuance again.
One place the whole conservative obsession with gay marriage may well be challenged in the courts of both law and public opinion is on these points of nuance. Conservative marriage activists are (as usual for conservatives) on the wrong side of history, on the wrong side of compassion, and on the wrong side of simple humane treatment of their fellow man. I for one would love to see their smug, arrant bigotry founder on the rocks of nuance.
That particular shard of justice would write itself in the poetry of love.