Let's be honest about this. Is there a segment of the American population who will never vote for Barack Obama under any circumstances because he is Black? Absolutely. However many people that may be, it is too many. Of course, the flip side of that question, one that never seems to receive any attention at all, is why Obama has essentially completely locked up the African American vote, and no one at all is calling them racist for supporting Obama purely based on his race.
That said, I have another question: Why is is that for all of the cries of racism, it is only the left that seems to be obsessed with it: http://www.progressive.org/mag/comment1008.html. I have plenty of friends and acquaintances on both the left on the right, and it is inevitably those on the left who bring up the subject of race, who focus on it, and who preemptively blame their candidate's loss next month (as an FYI, I think that Obama is going to win, but that's neither here nor there) on racism. To me, this is a sign of a defective mind, one that cannot debate ideas, policies or candidates on their merits, so it must fall back on shrill, bitter claims that the adversary is evil. It's pathetic, frankly.