Looking at the last 10 national polls or so, the real numbers are probably something very close to Obama 48 vs. McCain 43. The undecided voters will probably break towards McCain at a better than even rate, but to have a chance, McCain needs to close that gap significantly in October. In other words, he needs to hold Obama in place or pull him down a point or two, while raising his own numbers 4-5 points. That's a tall order, but not impossible.