Every early-voting report I've seen (e.g., Ohio, Florida, Virginia) shows Obama winning big among early voters; at the same time, in the same states, predictions are that Romney will win by fairly healthy margins among voters who wait until November 6. Why should that be?
First, it contradicts the earlier meme about an enthusiasm gap between Romney supporters and Obama supporters. More enthusiasm should translate into more early voters, and less enthusiasm into fewer earlier voters, right?
Second, this sets up what could be an Election Day of discouraging exit-poll results: if Romney's voters in fact are waiting until November 6, and a large percentage of Obama voters have already voted, wouldn't that be the inevitable result: a dayful of mass media reports that "Romney leads exit polls!"?
Third, since an ever-larger percentage of voters now chooses early voting over Election Day voting, how will these votes be accounted for (if they are accounted for) in the exit-polling results?
Answers? (A superior ground game by Obama could be one answer to the first point, and I hope it is. But that doesn't cover points Nos. 2 and 3.)