There's also plenty of evidence that Iraq had (known, small) stockpiles of chemical weapons, too (last I checked those were classed as WMD), which are widely accepted to be a likely cause of gulf war syndrome and a contributing factor to congenital disease in some parts of iraq.
Mind you: I'm not claiming that it's ethical to invade a country on shoddy pretenses.
Of course at one old point Iraq had WMD programs. But you were completely misrepresenting the situation by stating for the later period that "The funny thing about that conspiracy is that the WMD were real. Hussein had them, and and its true that he didn't give them up". Even the very article you linked stated clearly: "There was no evidence of any yellowcake dating from after 1991, the official said." As for the small amount of chemical weapons or precursors, they also have not been interpreted afterwhile has having any significance regarding the willingness to comply.
Saddam also received considerable material support from the US during the Iran-Iraq War -- those pictures of Donald Rumsfeld shaking Saddam's hand aren't fake. Lots of jokes about "we knew Saddam had WMDs cuz we gave em to him!" were, to a degree, credible on paper.
Saddam had long since stopped working on them, but made a point to look like he was. This allowed him to drum up support by posturing like he was standing up to the US, and also to look threatening to the Iranians (plus the Kurds + Shias).
I'm not justifying the actions of the administration or even the legal basis for it, but per my understanding, the claims were not untrue, notwithstanding how it was sold to the us public (especially as filtered by the complicit media)
http://www.nbcnews.com/id/25546334