Dean supporter here. Nothing against Clark as a candidate...
In terms of pure politics, I keep having to remind people that only two campaigns stand a chance against the $200 million Bush will amass against the nominee: Dean and Kerry. All of the other campaigns have accepted federal matching money, which limits them to spending $45 million until August. Even if one of the other campaigns should manage to be competitive with Dean for the nomination through March, they would be sitting ducks for the Bush media machine and legally unable to fight back with rallies, interviews, and advertisements from April to August. In 2000, Gore was silent for a month before the Dem convention because of these spending limits and lost a lot of his 10% lead in that time.
While Dean's grassroots support is phenomenal and unprecedented in modern politics, and I believe that many if not most of us would go on to work for the Democratic nominee, I am not naïve enough to believe that we can overcome a three or four month media blackout against the professional Republican spinmeisters and their friends in broadcasting
Howard Dean will win the Democratic nomination. His core supporters will not let the campaign fail. We can out-hustle and out-spend any competition. The longer this primary process lasts, the later we get to begin focusing the country's attention on the general election and the Bush record. The longer it lasts, the better chance Bush has of keeping his job. If I were a wealthy Republican, I'd be giving money to the Clark campaign, knowing that they will at least keep the Dean campaign distracted and, may even be able to capture the nomination but end up broke against the media onslaught.