Here is a panel discussion of Iraq, with Republican Senator Richard Lugar, and Democrat Senator Joseph Biden, discussing the present situation in Iraq, and plans for "Iraqification".

Biden is one of the Democrats I consider to be critical of Bush in a productive way, without being divisive, hyperbolic and partisan about it.
He is someone who clearly has the best interests of the country in what he says:

http://www.pbs.org/newshour/bb/middle_east/july-dec03/iraq_11-13.html