No, and the reason is those people are already being counted in polls. Though they are loud and repetitive, the only ones listening to them are each other. They've swayed about as many people as they're ever gonna sway, and at this point, most Americans, by far most, are completely sick of hearing their crap. Especially stuff about Muslims, and about Jeremiah Wright, and Bill Ayers. If that tactic were gonna work, it would have been reflected in the polls too.
McCain may make some last-ditch reference to Jeremiah Wright, but Obama is ready for that. His campaign is the best-funded ever, the most meticulously prepared. And when Hillary Clinton's supporters tried to bring up Wright, Obama deftly turned it to his advantage by making a brilliant speech about race issues, one which most Americans watched and which easily dispelled all the nonsense about him being Rev Farrakhan in disguise. If McCain brings up Wright again, Obama will likely give another speech, and Americans would watch. I don't know if you folks in the UK have watched any of Obama's speeches, but they're great ones for the ages. He's like Cicero.
In short, all the American racists have pretty much made up their minds, so it's not gonna be much of an issue. The only undecided people are ones who really don't care about race.