Politics is a hilarious sport, as subtle and intricate as a game of Street Fighter II, and this article nicely captures the reasons why. Don't bother reading it though. I'll give you the Be Kind, Rewind-esque summary:
MCCAIN: [fearmongering half-truth and distortion about Romney]
ROMNEY: [inarticulate shriek of rage, followed by:] You say you're sorry!
MCCAIN: I will not say I'm sorry! YOU say you're sorry -- to the TROOPS!
ROMNEY: [whimper of defeat]
RANDOM ADOLESCENT OBSERVER: Ooh, snap!
Meanwhile, Obama has whomped Hillary in South Carolina by a 2:1 margin. Go team! But of course that doesn't silence the critics who are still whispering that America isn't ready for a black president. Dude, how dumb are you? That's not the question. Of course American isn't ready for a black president -- in the abstract. But people are always ready and willing to crown an individual an Exception.
Margaret Thatcher and Golda Meir were both wonderful examples of this phenomenon. I doubt whether either country, if polled, would have said it was ready for a female leader; certainly they haven't elected one since. But the right person at the right time can make at least the majority of the voters, in societies that remain racist, sexist, and generally closed-minded, look past those traits.
It's a bit like going gay for just one person. I feel like the country can go gay for Obama, if you follow my logic. It's not exactly Dr. King's dream fulfilled or anything, but it's a start.