The advocacy groups would be rightly enraged but I do not feel that the Dem leadsership gives a sh!t. The end this war now ANSWER crowd will turn out in 2008 the military advocates will not turn out enough oppositon to dethrone Hillary and her running mate, Al Sharpton (just Kidding).
They have overtly started a fight over the supplemental, this gives Bush absolutely no outs. He signs it and gets some funds for the rest of his term or he gets bupkus and robs the rest of DoD to keep it going.
The real policy will be to continue making the Iraq war political, and damage Republican election hopefuls in the process.
Note that they have settled on trying to tell Bush when he can deploy forces, and all of this is meaningless.
The only real power they have is to curtail funding, and the public is not there ........yet. So they beat the bushes, looking for something to stick.