Don't Fall In Love With The Politician
The one thing the liberal base has in common with the conservative base is this semi-constant need to prove your ideological fervor. I've read and watched with amusement countless political-types who get propped up as the Spokesperson for the Liberal America only to get torn down or attacked the moment they do or say something third-wayish.
It's no surprise to me that both Howard Dean and Dennis Kucinich -both considered part of the Liberal Gold Standard back in 2004- are subjects of stories that shed them in a less-than-liberal light. Time and events change opinions, and anyone who's ever been in elected office can tell you that complete adherence to your political ideology will guarantee that a chunk of your voters will be isolated (and pissed).
So these guys have done what anyone who wants to still be in the game do: they adjust. That means occasionally doing things that piss off the base.
The bottom line is people need to stop falling in love with politicians...