Even Sarah Palin comprehends her candidate's undercutting doom:
[Romney] has said before that he doesn’t want to have to light his hair on fire. Well, there are a lot of his base supporters, independents who are saying, "Well, light our hair on fire, then!"
Like most everything Palin says, there's a deviousness in this. She no more wants a Romney presidency than Sean Hannity or Rush Limbaugh does, since the profitability of playing defense is considerably less than that of a rancorous offense. Still, she perceives correctly: Mitt Romney has a monumental base problem--those inextinguishable doubts about his religion and policy convictions--which would seem to be insurmountable, even if marginal.
Because--duh--it's that margin that generally carries swing states.