Feingold has no chance. The establishment won't back him and most Dem primary voters won't either.
Vilsack and Richardson are guys to watch- clearly both have at least a mild case of Presidential fever. Rendell is a maverick but could be a compromise option for the DNC.
Both parties have the system set up to favor the establishment candidate (possibly candidates in the Democrats case). Warner and Bayh are DOA, especially Warner.
Rendell could be a very good candidate for the Dems, but I'm told that there are things in his personal life that would not withstand the scrutiny of a presidential campaign.
