Saddam repeatedly refused to comply with UN resolution.
In August 1998, Congress urged a resolution that Clinton force Saddam to come into compliance. Not a single Senator voted no.
Again, in October 1998, without a single dissenting vote, the Congress voted for the Iraqi Liberation Act which called to remove Saddam to power.
Two months after that, President Clinton ordered that Iraq be bombed at known WMD facilities.
By the time Congress voted to authorize force in late 2002, there was broad based support that Saddam must be forced to work with the international community.
This is the point I have trouble understanding why the 'Rat revisionists don't get. Saddam could likely have headed off this confrontation by complying with the resolutions. But he chose the hard way, kicking out the UN inspectors and thumbing his nose at the international community. Saddam thought he could brazen it out, gambling that the US didn't have the brass to go in and kick him out. He won that gamble when Clinton was in office, but he lost when Bush got into office.
The 'Rats don't seem to understand that all Saddam had to do was comply with the UN resolutions and conditions that were placed after the first Gulf War. He chose not to do that, and thereby sealed his fate.