Here's what David Shuster has to say about polls over at Hardblogger:

I agree with all of you who have complained about the confusing poll numbers and the inability to determine who is really winning this election.

But, there is one number in all of these polls that both campaigns and the gang here at Hardball are paying very close attention to: The president's approval rating. Over the last week, based on eight national polls, the President's approval rating averaged 48.3 percent. At the low end was the CBS/NY Times poll at 44 percent... at the high end was CNN/USA Today/Gallup at 51 percent.

This number is incredibly important because of history. If you look back over the last 40 years, an incumbent president seeking re-election has never received a portion of the raw vote that was higher than his approval rating. Furthermore, in every election where the president's approval rating was below 50 percent, undecided voters broke heavily for the challenger. In other words, most analysts predict that the President will not go above his approval percentage... though John Kerry could see an election day bounce of a few points.

Shuster goes on to say that history could be thrown out here because we are at war, and he brings up a Greenberg poll that perhaps confirms this notion. I'm a bit skeptical that history does not matter in this election--I tend to think that the elecorate has not significantly shifted in about a decade--but I could be wrong. Nevertheless, the fact that the President's approval rating is sitting at about 48% does not bode well for his reelection chances.