Following up on the claims of E.J. Dionne and others that the Democratic base is unified and that Dean will have enough time to move to the center, here's some info from the latest USA Today poll. Respondents were asked if they were certain to vote for their candidate or if they might change their mind. Here are the results for likely voters in a Bush vs. a generic Democrat matchup:

Certain for Bush: 44
Bush, but might change mind: 12
Democrat, but might change mind: 13
Certain for Democrat: 27

This means that going into the election year, Bush has a 17 point advantage among certain voters and his 44 percent puts him in striking distance of the 50 percent needed for victory.

Now here are the numbers for a Bush vs. Dean race:

Certain for Bush: 47
Bush, but might change mind: 12
Dean, but might change mind: 17
Certain for Dean: 20

Bush has better than a 2:1 advantage among certain voters and is nearly at a majority. That gives him a much better base from which to go after leaning and undecided voters. Yes, all of this can change, but it indicates the struggle ahead for the Democratic nominee, particularly if it is Howard Dean.