Your recollection does indeed suck. Not only is your premise wrong but you are also clearly lacking any detail of the political climate at the time.
The bush admin pushed for war with Iraq, not because that's what the intelligence told them, it's what they told the intelligence community to find. People in congress didn't believe it, it's just that they never thought a sitting president and his admin would outright lie to them, to their face.
Of course people like boomerang don't remember that, they don't want to.
The Bush Admin fashioned 9/11 into a bludgeon against all enemies, foreign & domestic, in what has to be one of the greatest propaganda campaigns in history. Pandering to fear & bloodlust, they whipped the media into a frenzy & convinced all too many people to support their iron fisted leadership in time of a trumped up crisis. Hell, they even built an extra-legal prison at Gitmo as a publicity stunt to show us just how grave the threat was & how tough they'd be to overcome it. Breaking terrarist balls at Gitmo, defying any soft headed do-gooders to do anything about it cuz no true American would want any less.
For a lot of Dems, voting against the perfectly timed AUMF right before the midterms would have been political suicide. A lot of them got clobbered anyway. The whole effort was covered by a lot of talk about how the Admin needed it to "negotiate" with the stubborn Iraqis, something Hillary alluded to in her speech at the time.
As you say, it was hard for anybody to think that the Bushistas were lying about nearly all of it. In retrospect, I'm sure that a lack of experience with the personalities involved played a large part in that.