Seems to me that Dean is a Hillary plant. After he makes an absolute fool of himself with his mindless rantings, Hillary can walz in and look,... oh so moderate and reasonable.
Nothing happens in government or politics without some rational planning of the impacts, and possible outcomes, both short term and long term. And the Clintons are nothing if not PR schemers and planners.
Possibly. The only way I can think of to pull that off would be to let him run wild through the 2006 elections, then blame him for the Dems getting crushed at the polls. Follow that up with a very public firing and enshrine a well-groomed 'moderate' on the DNC throne, and watch mainstream America over-correct right into your camp.
Ack! That actually might work!