Obama hasn't been trying to run as a 'black' candidate, as Jesse or Al did/would, because you can't become president promising to elevate 15% of the population above the others., so wisely, he has tried to avoid any mention of it. But Clinton injected it (mostly Bill), and Hillary got her arse handed to her---but there might have been an effect, because Obama had only 25% of the white vote in SC, (vs. 36% in Iowa)