A nice explanation at Washington Monthly: If Same-Sex Marriage Is So Popular, Why Does It Always Lose at the Ballot Box?
This is still a key talking point of SSM opponents, that gay marriage hasn't won a referendum yet. There are two reasons for this: first, most of these referenda on constitutional bans took place years ago when there was less popular support than there is now, and, second, most of them have been in states where support was lowest. There was a wave of them in conservative states in 2004, which helped turn out the base for the presidential election. California in 2008 may have been the highest-profile case, but it was also exceptional.
He doesn't get into it there, but there are pretty obvious reasons for this. The votes on the subject have in most cases been for constitutional amendments to overturn a judicial ruling in favor of same-sex marriage, or to preempt an imagined one. Those campaigns are run by opponents. Proponents of same-sex marriage have indeed been ahead of the public-opinion curve, but they also usually have little motivation to legalize it in a referendum even if they possibly could. They generally regard marriage as a basic civil right that shouldn't be determined by plebiscite. Referendum campaigns are also generally ugly affairs, in which opponents have a strong motivation to drum up anti-gay fear in the general population.
Nowhere is this clearer than in New Jersey. Same-sex marriage has pretty clear majority support there in opinion polls. The legislature attempted to legalize it by statute, but it was vetoed by Governor Chris Christie, who said he thought there ought to be a referendum on it. Gay-marriage supporters refused to take the bait, saying that they'd work on overriding the veto in the legislature instead, even if it took longer.
2012 looks like it might be slightly different, since referenda are happening in the fall in three states where a win is actually possible, with varying degrees of likelihood. Washington state and Maryland have both passed laws legalizing same-sex marriage, but both states have provisions allowing opponents to force a referendum. If they can collect the necessary signatures (which is likely in both cases), the law doesn't take effect until the referendum passes.
Meanwhile, Maine is actually having a referendum to pass same-sex marriage by law, because they went the Washington/Maryland route in 2009 and the law was rejected by referendum then. I suppose there would be a referendum whether they went through the legislature or not.
I think I'd score Maine as the most likely place for a win, with Washington in second and Maryland third. Opponents are trying all the usual scare tactics in Maine, but the 2009 vote was fairly close, it was an off-year election (albeit an unusually high-turnout one), and opinion has continued to shift. One thing about Maine is, it's completely surrounded by jurisdictions where same-sex marriage has been legal for some time, so the more lurid fantasies about what happens in SSM states are probably not going to fly.
Matt McIrvin's Steam-Operated World of Yesteryear
- Referenda on same-sex marriage