Did you ever wonder why John McCain is not way ahead of a radical like Barak Obama in a country where a majority of voters describe themselves as right of center?
The answer is that McCain keeps slapping conservatives in the face.
He knows that on issues like immigration, his partnership with Teddy Kennedy, McCain-Feingold, etc. he has serious problems with his base but instead of reducing these concerns about him he continues to make the best possible case that he is not a conservative.
Check out his convention's speakers list.
At most he has included 4 conservatives and left scores of conservatives off the agenda. Where are Mike Pence, Eric Cantor, Paul Ryan, Tom Coborn, Jim Demint, Jon Kyl, ..... They are the most attractive faces of the Party but they are no where to be found.
If he does not pick a real conservative like Cantor for VPhis chances of rallying a majority of voters may go out the window. Remember George Bush lost the popular vote in 2000 by going against his base (less vigorously than McCain is.)