That's crap. Anybody who was even remotely paying attention, and who bothered to read even the stories in mainstream media all the way through to the extensions on page ten, KNEW the justifications for the war were B.S. Specifically, it was public and clear that (1) we had Iraq surrounded and Saddam posed no current threat to anybody, (2) if he had any weapons program at all, which the inspectors who actually had been on the ground said he did not, it was weak at best, (3) Iraq had no connection with Al Queda, (4) there was no attempt to purchase Uranium in Africa, etc. etc.
The vote mostly went as it did not because our representatives in Washington were fooled, but because they didn't dare say what they knew to be true: the case for the war was all lies from the get-go. That authorization wasn't justified even if you thought Saddam was a bad guy we'd have to deal with sooner or later, which some of them may have thought. The authorization was granted because they were afraid to be called "weak on defense."
More crap