I seem to remember that at the time the case based on his internal actions was pretty sound. That wasn't winning the general public over (who, let's face it, are pretty difficult to motivate into caring about some brown people halfway across the world) so the case was made for missile-based WMDs.Fair observation. Except we didn't go to war based on what Saddam might have done to his own country (he had been happily gassing for quite some time and we didn't feel the need to intervene), it was on the risk he posed to the West, and it is the level of that risk which is/was under debate.
As far as I'm concerned, the moral case for the war already existed but more was needed to sell it to the same public who said "Where?" when the UN refused to help in Rwanda and applauded Labour for not intervening in Syria when it was so desperately required.