Some of the stated reasons to go into Iraq before we did:
-Self-defense
--find and eliminate weapons of mass destruction, weapons programs, and terrorists (UN inspector Scott Ritter wrote that Iraq is not disarmed)
--collect intelligence on networks of weapons of mass destruction and terrorists (Saddam aided Hamas and thier fight in Isreal)
-Humanitarian
--end sanctions and deliver humanitarian support (According to Madeleine Albright, half a million Iraqi children had died because of sanctions.)
-United Nations Security Council Resolution
--Resolution 1205, made in 1998. (one of 14 resolutions that were not kept, this one ended with the threat of hostilities)
-Regime Change (to democracy)
--end the Saddam Hussein government (and put power to the people)
--help Iraq's transition to democratic self-rule
--stop the filling of mass graves
--close down true torture rooms and rape rooms run by the Hussain brothers and the military
-Economic
-secure Iraq's oil fields and other resources for Iraq's economic expansion
-Militaristic
--end remaining hostilities left over from the previous excursion in to the Persian Gulf (Iraq was defying the cease-fire by shooting at Allied warplanes enforcing the No-Fly Zone)
Course, Iraq was dangerous enough for Bill Clinton to bomb a few times (some oddly enough corresponding to various parts of his impeachment investigations.... hmmmm....), for John Kerry to state that if you don't like the Gulf war, don't vote for me, for John Edwards to call Iraq a Clear and Present Danger (no one in the Bush Administration used those words before or since).
The Democrats helped to authorize the war. If they were so worried about the justification prior to it, why didn't they raise a red flag then? This is a case of thursday morning quarter-backing (monday is usually reserved for when you first find out some details, tuesday is injury reports or in this case, the "questionable" report made by Joe Wilson, wednesday is hump day and all the senators were out, well....).
Al Gore himself eulogized the soldiers killed when F-16's shot down a US helicopter killing all on board "in the name of the UN"....