Jimmy Carter looked like a lead pipe cinch against Reagan in 1979. He crushed Reagan in all sorts of national polls, except the one that counted. Asking people what they think about an election nearly 2 years hence in almost meaningless. Far from suggesting that a Palin candidacy is in trouble, this poll indicates the reverse — that polling data can't be trusted as an indicator of her prospects.
All this hyperventilating about Sarah Palin is pointless and unseemly. Either she is what the caricaturists say she is, in which case she'll fall flat on her face, or she isn't, in which case she will have as good a chance of beating Obama as anyone Republicans could nominate. What will be, will be and today's polls won't affect it at all. Ignore the polls and let events unfold.
Obama isn't very smart on his own, but I think he will likely avoid the mistakes Carter made. No doubt the media will savage any candidate put up in opposition to their Messiah, but the knives are out for Palin in double portion.