It it the angry white male who will show up in droves to vote for McCain?
Is it the far right who will show up because of Palin?
I don't think they can much more than they did in 2004. This is one majority that isn't silent. The big question is whether Palin is enough for McCain to connect with these types of voters to the degree that Bush did.
Is it a huge minority turnout for Obama?
Is it a huge turn out of young people for Obama?
maybe, but these voters are notorious for saying they're going to vote and then not doing so.
Is it the Bush haters who have been waiting for this election day for 8 years?
etc, etc, etc
no, there was 2004. However, Bush has succeeded in turning an entire generation against the Republican party. That will hurt McCain, and it will hurt future Republican candidates more when more of them reach voting age and start to actually vote.