I think that argument is pretty much over.
None of the leading Democratic candidates are calling for immediate pullout, and certainly none of the Republicans. Some leftists in Congress are going to make a big hairy thing of themselves for months to come, but they can't do much about it.
I hear a lot of people saying that Iraq will just easily clean up al Qaeda on its own without us. I don't think they know how hard the fight has been, how al Qaeda controlled large populations with sheer terror, or how fragile the current victories are.