The argument you raise would be valid if it weren’t for the fact that most of those 100+ Congressmen and Senators never changed their stance, even when war was imminent. If their vote is not indicative of their actual stance, then surely we should have 100+ examples of these guys speaking out against their earlier vote and demanding that we not go to war in early 2003, right? After all, these were the days when we all knew that our troops would be hit with WMD in the ring of fire around Bagdad, so if they were truly against the war why in Gods name didn’t they speak up?