Clinton's biggest mistake, as I see it, was her vote authorizing the use of armed forces against Iraq. I protested against the war at the time, and I've since written about the problems with it. I was angry with Clinton, especially, for what I saw as a betrayal of her values for politcal gain.
Then last year I read an analysis of that vote that made me rethink my position on Clinton. According to the columnist, the problem facing the Senate was that Hussein was not allowing UN weapons inspectors to do their jobs. The possible solutions were a) leave things as they were; b) find a way to put pressure on Iraq to allow the UN weapons inspectors to make sure that there were no WMDs; or c) invade Iraq. Clinton wanted option B. The bill itself gave the president the authority to invade if he thought it necessary. In other words, options A (if the bill failed) or C (if Bush decided he needed to invade.) By voting yes, Clinton meant to give Bush another weapon in his diplomatic arsenal to pressure Hussein into admitting UN weapons inspectors. Bush used the vote to say, "Screw the UN. Let's invade!" So yes, it was stupid for her to vote that way. But it wasn't as black and white as it's been portrayed.
Here is Clinton in her own words, explaining her vote:
My vote is not, however, a vote for any new doctrine of pre-emption, or for uni-lateralism, or for the arrogance of American power or purpose -- all of which carry grave dangers for our nation, for the rule of international law and for the peace and security of people throughout the world.
Over eleven years have passed since the UN called on Saddam Hussein to rid himself of weapons of mass destruction as a condition of returning to the world community. Time and time again he has frustrated and denied these conditions. This matter cannot be left hanging forever with consequences we would all live to regret. War can yet be avoided, but our responsibility to global security and to the integrity of United Nations resolutions protecting it cannot. I urge the President to spare no effort to secure a clear, unambiguous demand by the United Nations for unlimited inspections.
The full text can be found here:
http://clinton.senate.gov/news/statements/details.cfm?id=233783 On the plus side, she has stated that the Iraq war is a mistake and that she wants to find a quick, reasonable way to end it.