Noam Scheiber (sub. req’d.) points out that Dean’s desire to strengthen the Democratic party over the long haul could conflict with its short-term needs:

“You can’t sacrifice ‘08 for the benefit of 20 years from now,” says [major Florida donor Chris] Korge, who is generally supportive of Dean. “The country just cannot afford it.” . . .
Dean’s moment of truth will come in March 2008, when a Democrat effectively locks up the presidential nomination. If the past is any indication, the nominee will insist on boring in on the 20 or so states most likely to clinch 270 electoral votes. But Dean, according to those who know him, will continue to insist on funding his 50-state strategy. “Any Democrat running for president needs to understand that … Howard is not going to throw that over the side of the ship,” says Steve Grossman, a Dean ally and former DNC chairman. And if they don’t? “It’s going to be a tough conversation.”