One of the arguments conservatives have made in their criticism of the Prop. 8 decision (see here, for instance) is that, according to some reports, trial judge Vaughn Walker himself is gay, which obviously means he can't be impartial in this matter. But this has uncovered a problem that could lead to a serous legal stalemate.
As opponents of marriage equality often say, letting gay people get married will undermine traditional marriage. How, exactly, they aren't quite sure, but they're sure it will. Which means that straight judges have as much of an interest in this case as gay judges -- after all, it's their marriages that are at stake too. One of the subsidiary arguments is that marriage is for the purpose of procreation. So how could staunch procreator Antonin Scalia (who has nine children) possibly be impartial? He obviously has to recuse himself when the case reaches the high court, as do most of the other justices, who have been engaged in opposite-sex marital conduct at one time or another. The exceptions are Sonia Sotomayor and Elena Kagan, neither of whom has ever been married. But that doesn't mean they could hear the case impartially either -- if marriage is undermined, they might never find mates, after all.
So neither straight judges nor gay judges can really objectively evaluate this question. Who knows what the Court will do?
-- Paul Waldman