I think Clarke is Dean's main rival, so I don't think they would get along either. Also, Clarke has a history of "going off the reservation" (just ask William Cohen, Clinton's Sec. of Defense). Dean needs someone submissive (politically speaking). Maybe Sen Durbin (D-Ill)?
Durbin has been asked if he would ever consider being on the ticket as the VP candidate. He stated that he would never want to be Vice President, because he likes to handle things his own way, and make his own achievements and mistakes. A Dean/Durbin ticket, or Anyone/Durbin ticket, a'int gonna happen.
Sorry my Republican friends