Three justices of the Iowa Supreme Court were defeated for election to new terms on Tuesday. It is as clear as could be that they lost because they had joined in Varnum v. Brien, 763 N.W.2d 862 (Iowa 2009), the court’s unanimous decision holding that the state constitution gives same-sex couples a right to marry. Especially given that Iowa is a relatively moderate state – it has a Democratic Governor but just elected a Republican one; it has two long-standing Senators, one Republican and one a liberal Democrat; and Obama thumped McCain there in 2008 – one might well expect that high court judges in other states will take note and be more hesitant than they might have been to follow in the same path as Varnum.

So how can I possibly say that the vote in Iowa may improve the long-term chances for same-sex marriage? Because many people have a strong resistance to making this a judicial issue. And given a steady change in social attitudes, I think advocates of same-sex marriage have a much better chance long-term if the battle is fought out cleanly over whether a state should allow the practice, rather than over whether the practice ought to be constitutionally required.

So I believe judicial decisions requiring states to countenance same-sex marriage are unlikely to resolve the issue nationwide but are very likely to fortify opposition. And if advocates of same-sex marriage focus efforts on winning in legislatures and plebiscites rather than in court, I think their long-term chances of success are improved.

We’ll never know for sure, but it may turn out that the Iowa vote helps shift the battle to ground that is more favorable over the long haul for the widespread acceptance of same-sex marriage.