Interesting post I must say...I can never predict what story awakens the Elephant inside of you CS...the "support McCain and you are a racist" game is one that I don't think really exists outside of political commentators that I've never heard of. However, I do believe that a good 5-6% of McCain supports would not support Obama purely on race. This is backed up here...I know it's the New York Times but what can you do? Interestingly on a completely unrelated note, that is about the population of African-Americans that support McCain.
The real thing that will win this election for Obama has nothing to do with him at all; it is the candidacy of Bob Barr. Let me digress...in 1992 I was voting for President in mock election in middle school so I don't really remember the events first hand but how on earth was Bill Clinton able to persuade the American people that he would be able to create change? The answer is he didn't, Ross Perot messed things up for Bush. The same thing could happen here as Barr polls pretty high in both Nevada and Ohio and who knows what the reaction will be when McCain picks Lieberman as his running mate.