Don't forget that at the time of the sabre rattling against Iraq the Dems were not in control of the situation and found themselves in danger of being labeled traitors. Remember Freedom Fries?
As far as getting out, there is a pretty well founded belief that to end the war and just exit the arena would lead to an all out civil war in Iraq with Iran ending up the winner over everyone else.

We're talking about a people that hold a pretty long grudge so I think that if they do manage to be peaceful long enough for us to say "Mission Accomplished" (for real this time) and pull out then they'll just launch into it then. So why stick around?

I feel that this last maneuver by the Iraqi gov't was a convenient campaign year gimmick that allowed us to break a long standing truce with an anti-occupation cleric under the guise of the Iraqi gov't taking up security of the country.