Now if you aren't happy with the evidence then attack the CIA who gathered and presented it. Demand that heads roll at CIA HQ.
And who makes heads roll at the CIA HQ? Oh, yeah, the executive branch. See, the CIA, like the military, ultimately works for the president. The president gets the blame and the criticism because it comes with the job. He is the head of the executive branch, so any screwups from below are still his problems to deal with. I have always been against our invasion of Iraq because regardless of the justifications for removing Hussein, no one ever said how we were going to accomplish the stabilization of it when he was gone. Nothing had changed since Bush Sr. decided not to depose Saddam after Desert Storm. The power vaccuum was still there. In fact, things were worse because all the sanctions against Iraq throughout the 90's had driven one of the richest, egalitarian, and secular societies in the middle east into a nation filled with poverty. We then remove the only thing holding the country together and replace it with various incarnations of incompetence.