This says more about the American public's intelligence, or lack of, then that of the former President's intelligence.
I thought that I was paying close attention, but I did not ever hear Pres. Bush assert as incontrovertible fact that Saddam Hussein has a heap of functional and deployable WMD.
However, I do have a file of published statements of many high ranking members of The Congress and cabinet members, both Rep. & Dem. that did so state, or very nearly so, during late 1990s and early 2000s.
And, not to put too fine a point on the matter, but a single 20 liter carboy of certain chemical substances can constitute a WMD. I seem to recall that some such discovery occurred in Iraq.
Don’t forget the unrelenting media campaign. It is tough for many to get beyond that.