But there are a couple things a politician and his staff learn over the course of a campaign that come in handy once in office: message control, disaster response, even basic PR. These aren't skills that help a politician govern well, but they are skills that help him stay out of trouble and keep him from embarassing his party. As Jason Zengerle notes in TNR, Roland Burris illustrates this perfectly. If Burris had gone through an election for the seat he currently occupies, he and his staff would be far better equipped to handle the almost daily mini-crises that seem to emerge around him. And President Obama wouldn't have to compete with his Senate successor for airtime.
Of course, if Burris had gone through an election for the seat, all of his funny business in Blago-land likely would have come out and he wouldn't have been elected in the first place. Not that that's such a bad thing, either.