Well said, Melody, but I see it from a different angle. At the time of the vote it was not clear whether or not WMDs existed. The only way to know for sure was on-the-ground inspections. Bush (correctly, I think) said that Hussein would never allow inspections unless there was a threat of war.

Where Bush lied was in his assurances to Congress that he would not go to war if inspections did not show WMDs.

Congress could have rescinded permission, but they did not. They still have not.