Juan R. Cole, a Middle East expert and professor of history at the University of Michigan, who has an excellent weblog, says:

The commentators on cable news shows on Sunday seemed to think that Saddam's capture guarantees Bush's reelection in November of 2004. Well, incumbents have great advantages, and most often do get reelected. But Saddam won't do it for Bush. In a way, the capture came too early for those purposes. It will be a very dim memory in October, 2004.

The Sunni Arab insurgency will continue at least for a while (see below), and the possibility that the Shiites will make more and more trouble cannot be ruled out. The US military is stuck in the country for the foreseeable future at something approaching current troop levels. The move to give civil authority to a transitional Iraqi government may not go smoothly. The administration will have to ask Congress for another big appropriation for Iraq sometime before the '04 election, and that won't help Bush's popularity. The Iraqi economy is still a basket case, the oil pipelines are still being sabotaged or looted, and a whole host of everyday problems remain that having Saddam in custody will not resolve. If Iraq is still going this badly in October of 2004, it would be a real drag on the Bush campaign. Yes, I said "this badly." One arrest doesn't turn it around, except in the fantasy world of political theater in which pundits seem to live.