This polling report (about a year old, but still indicative) suggests that there’s not much support for amending the U.S. constitution to prohibit same-sex marriage. When you look at these results (see questions 50-52), the trends are hard to make out. As nearly as I can guess, opposition to same-sex marriage has probably declined somewhat, but the numbers bounce around a good bit, perhaps in response to things like attempts by local officials to offer gay couples the opportunity actually to marry and like a national debate. So we don’t know what public opinion would look like at the end of an extended and focused national debate. Don’t get me wrong: I don’t think we’d be at 70-30, but 60-65% opposition isn’t out of the question. (Thus the percentage opposed was 53% in July, 2003, but bumped up to 63% in response to Gavin Newsome’s antics, falling back down to 53% in July, 2005, after many months of no news.)
But as the Pew analysts note, opposition to gay marriage doesn’t translate into support for amending the Constitution. I would, however, add: at least as long as there is no federal judicial provocation, which might send opposition to gay marriage and support for a constitutional amendment soaring.
Of course, state constitutional amendments upholding traditional marriage tend to be big winners wherever they’re offered. "The people" may agree with Rauch that this is a matter for states. Left to their own devices, many, perhaps most, states would legislatively or constitutionally prohibit same-sex marriage and a few would permit it.
This leads me to offer some unsolicited advice to advocates of same-sex marriage, on a point on which I hope we can agree. The surest path to establishing same-sex marriage is through a legislature. Litigation, or anything that appears similarly high-handed, courts (so to speak) a backlash, likely increasing support for legislation or constitutional amendments upholding traditional marriage. What’s true at the federal level is in these cases likely to be true at the state level as well. In any state where a court decision favoring same-sex marriage is likely to withstand the inevitable backlash, the legislature would have been likely to pass it in the first place. So stick with legislation. I’ll argue with you...civilly of course. And I expect you to return the favor.