Part of me thinks there is a certain element of US's enemies that is happy to see the US forces in Iraq, and are in no big hurry to see them leave. A group like A.Q. for example is perfectly happy to have a place to engage US in guerilla warfare, keep them busy, and the welfare of the Iraq people is not their primary concern. Ergo A.Q. would have preferred Bush stay in power longer, or that a guy like McCain get elected. Just a hunch, I can't exactly prove it.