...was done purely for political expediency. He was hedging his bet because he knew that during his upcoming presidential campaign, had the war been a amazing success, tons of WMD found, AND/OR finding a connection to OBL, there would be no way to challenge that. His campaign would be solely on domestic issues.
Granted the chance for any success in Iraq should have been easily dismissed. If there ever was WMD, and the ability to deliver Anthrax and nerve agent to the East Coast, don't you think Hans Blix and the UN would have found any evidence? But I digress.
Kerry and Edwards were in a position where they had to vote for resolution that gave the President the authority to invade Iraq because the Administration did a decent job selling this war to the American public. Bush publicly started to beat that fucking war drum just after 9/11, and a lot of Americans bought it. We all know, however, from reading Suskind's book on Paul O'neil (if you haven't read it you really should) that from the very begining of the illegitimate Administration the war in Iraq was a high priority:
The hour almost up, Bush had assignments for everyone. Powell and his team would draw up a new sanctions regime. Rumsfeld and Shelton, he said "should examine our military options." That included rebuilding the military coalition from the 1991 Gulf War, examining "how it might look" to use U.S. ground forces in the north and the south of Iraq and how the armed forces could support groups inside the country who could help challege Saddam Hussein. Tenet would report on improving our current intelligence. O'neill would investigate how to financially squeeze the regime. Meeting adjourned. Ten days in, and it was about Iraq. (Suskind, "The Price of Loyalty", 75)
I thought so early they would have wanted to focus on the important issues like economics, health care, education, the environment, the 35 million people living in poverty... Nope. Let's cotinue from where we left off, with the same people (most notably Cheney and Rumsfeld) and kill that guy that tried to kill my dad.
Don't blame the senators for voting for the war. The USA Patriot Act, perhaps, but not the war. The were lied to and leaned on, and they had their minds on the future. They were thinking safety, viability in 2004. Clark and Dean had the luxury of not having to cast a vote for the war. I am not suggesting which way they would have voted, either. But Dean's early anti-war angle was a gamble that eventually became his meal-ticket. Let's face it. Dean would not have been on the map had the war gone as well as Bush had hoped. And then the only guy that would have looked good would have been someone who voted in favor of going to war.