Gore’s endorsement of Dean clearly adds to Dean’s already considerable momentum toward the nomination. At the same time, as Josh Marshall points out, it probably will accelerate the emergence of the anti-Dean candidate, whoever that may be. Trouble is, of course, that being the anti-Dean, with this announcement and Dean’s latest poll results, seems increasingly likely to mean a ticket to a glorious second place finish in the race.

But that means it’s more vital than ever to think through the question of whether and how Dean will be able to move to the center in the general election. And make no mistake about it: he will need to do so. In the Gallup poll linked to above, Dean does way better among liberal Democrats than any of the other candidates, receiving 40 percent of their support, compared to just 11 percent for Clark and 9 percent for Gephardt.

But when you look at moderate and conservative Democrats, it’s a different story. Dean receives only 17 percent of moderates’ support, running slightly behind Clark at 19 percent. And with conservatives, he does rather poorly, receiving 11 percent of their support, running behind Gephardt (25 percent), Clark (17 percent) and Lieberman (13 percent).

It’s a fair assumption that the pattern we find here among Democrats will replicate itself in the general election: liberals will take to Dean easily, while moderates and conservatives will take much more convincing to throw their support to the man from Vermont.

Findings from a recently-released Pew Research Center poll of likely Democratic primary/caucus participants underscore this problem. Just 5 percent of these Democratic voters choose Dean as a Democratic candidate who would do a “particularly good job” protecting the nation from terrorism (and respondents could select more than one candidate if they wished). Now, if Democrats have a hard time associating this issue with Dean, it’s a reasonable assumption general election voters will have an equally or more difficult time.

The Pew poll also finds that just 36 percent of these likely Democratic primary voters favor repealing all of the Bush tax cuts, as Dean does. This is actually less than the number (42 percent) who would prefer to repeal the tax cuts for the wealthy, while keeping the rest of the cuts in place. And this is among Democrats. It’s a very fair assumption that Dean’s position will be an even harder sell among the general election electorate–particularly the moderates and conservatives mentioned above.

So: time to move to the center. Here’s a two point plan that could help him get there.

1. A “Sister Souljah” moment on the loony anti-war left. Dean, as Robert Kagan and others have pointed out is no George McGovern on foreign policy and fighting terror. Time to let the voters know that. There is certainly no dearth of nutty groups or far-out intellectuals who could be usefully denounced as failing to understand the need for America to fight terror with every means at its disposal. Iraq may have been an ill-conceived use of American power, but that does not mean the exertion of American power is always a bad idea. And so on.

2. Preserve the middle class tax cuts. As Paul Krugman and others have pointed out, eliminating all the Bush tax cuts is not economically necessary. And the polling data couldn’t be clearer about what a bad idea it is politically. Time to tell the American people the really serious problem with the Bush tax cuts is the huge tax breaks going to the folks who don’t need it. We’ll take those back, then move toward real tax reform that shifts the tax burden away from work and closes tax loopholes for the wealthy. And so on.

Together, these two moves would do much to reassure non-liberal voters who are uncomfortable with George Bush that it’s safe to vote Democratic. And that, in DR’s view, will be the key to the election.