All of it, here.

The central point is this: if McCain has gained ground — and most likely he has — then what he’s done is reset the race to roughly where it was two weeks ago, when Obama also had roughly a 6-point national lead. Except, the two positions aren’t entirely equal, since two weeks have run off McCain’s clock. Roughly speaking — and accounting for his inferior position in the electoral college — McCain needs to gain about half a point per day every day between now and November 4 to become a favorite in the electoral college. That is not an easy task; from the nadir of Obama’s numbers, which we put at 9/12, to his peak, which we put at 10/11, Obama was gaining about a quarter of a point per day on average. That is, by the standards of a presidential campaign, very rapid movement. But McCain needs to get those numbers down about twice as quickly as Obama got them up, and he does not have any debates or other major public events to assist him.