Nancy Pelosi has a problem. Fundamentally, she - and the Democrats in general - have to do two things in order to have a good chance at holding on to Congress in 2008 and getting the White House as well.
First, they need to deliver for their base. Because when one takes a cold, hard, look, the money and the ground troops largely come from the DailyKos and other sites like that. This is in addition to the AFL-CIO, NEA, and other parts of their base.
Second, they also have to show that they have some degree of competence in matters of national security. The Clinton Administration certainly did not do so. And there are many in 2006 who went with them out of frustration with the GOP more than any love for the Dems. But if the Dems start looking like they will cut and run, they could be in serious trouble with the center.
But their base wants them to cut and run. They want withdrawal, sooner rather than later. See the missive by Michael Moore as an example. This base has shown that they can knock people off in the primaries. Just ask Joe Lieberman. And a number of states do not permir primary losers to run as independents.
So, for self-preservation in the primary, their base has to be happy. But if they cater too much to the "anti-war" element of their base, as the GOP did with the social conservatives in 2005-2006, they could lose the center and alienate other parts of their base. But if they are too nice with the Administration - and if they don't pull out of Iraq, the anti-war base will be upset, and could topple several Democrats. Steny Hoyer and Jane Harman could be targets of such an effort.
So far, Pelosi has shown that she tend to lean towards keeping her base happy. She pushed Murtha as majority leader - and lost by roughly 2-to-1. She settled her grudge with Jane Harman, but then had to pass over her choice to chair the House Intelligence Committee because of his past (which included losing his position as a federal judge). That probably did not go over well with the Congressional Black Caucas.
What will probably happen? At first, there will be some cooperation. Comprehensive immigration reform will pass - Democrats will want a major accomplishment, the President will want the same. A fair number of the Republicans will also go along - many eager to show they can solve problems, too. A similar deal may happen with the minimum wage.
After that, Pelosi's headed for a train wreck. Sooner or later, Iraq gets debated. That is when the anti-war base will find out that a number of Democrats don't want to cut-and-run. Any effort to do so will be defeated, and then all hell breaks loose on the left. By this time next year, we could be going into the 2008 Presidential primaries with congressional Democrats engaged in fighting amongst themselves, with the DailyKos/DU wing openly targeting those they deem ideologically impure, and the largely unified Republicans watching the show.
That is a bad position for Pelosi to be in.