Just to follow up on Judis's post and the prospect of undecideds going overwhelmingly for McCain, I thought I'd point to this interesting piece of analysis from GOP pollster Steve Lombardo:

It is our sense that Team McCain has finally settled on a single message strategy (taxes and socialism) that will appeal to a large segment of undecided voters.  An analysis of our own surveys—as well as three recent national polls—suggests that current undecided voters lean a little more male, and tend to be older and less-educated white voters from the rural Midwest.  They tend to have voted for Bush in 2004.  It is important to note that we do not believe that these late-deciders are going to go with McCain because of some kind of “Bradley Effect.”  Many of them will vote for McCain because they are ideologically aligned with him, not because of race.  Finally, even if McCain wins late deciders by a 2 to 1 margin he still falls short by several points.  He would have to win 80-90% of the late deciders to even have a chance at victory, and that is (obviously) extraordinarily unlikely.  [Emphasis added.]

--Jason Zengerle