Blissful Ignorance
There's really something bizarre about the growing number of constituencies to which your modern-day Republicans must pander in order to succeed in primary politics. That's all I think you can conclude from something like Mitt Romney calling on the US to boycott a UN panel we're already boycotting. Of the people in the race, Romney's clearly the one who's most eager to leave no pander unturned, so here we have him grasping at straws to prove his UN-hating bona fides, probably just wishing he'd had the chance to pick a fight over parking tickets like Rudy. Maybe then he wouldn't end up making an ass of himself like this.
Obviously, though, you can't put this sort of ignorance on a par with a "gaffe" like getting a haircut or saying you wouldn't drop nuclear weapons on Pakistan.