Ambition as a Virtue
Maybe it's just 'cuz I'm an asshole, but I find myself a lot more sympathetic to Tommy Carcetti than a lot of Wire-watchers seem to be. It's his very cloying, grating, somewhat unprincipled ambition that, I think, makes it plausible that he'd be a good mayor. Politics is not, at the end of the day, a game in which the pure of heart are going to succeed, so you can just cross that option off your list of possibilities. What Carcetti has going for him is that he's clearly not the kind of guy who's going to be satisfied if his last job in politics is Mayor of Baltimore. To take the next step and become governor or senator and nurse vague ambitions for the White House he's going to need, on some level, to do well as mayor and improve the city. By contrast, you see a more pernicious type of politician in Clay Davis and Clarence Royce -- men who lack higher ambitions and are therefore motivated primarily by veniality.
Race, as it so often is in American politics, is extremely relevant here. The record of African-American politicians running in majority-white constituencies is depressingly bad. As a consequence, African-American politicians holding jobs -- mayor, congressman, city council, state legislature -- in majority-minority constituencies tend to face sharply constrained horizons and therefore have incentive to settle for merely venial, rather than ambitious, conduct in office to the detriment of the communities they serve. Nowadays, of course, we have rising superstar Barak Obama and if he's joined in the Senate by Harold Ford we may have something of a trend on our hands. That would be a good thing on its own terms (and, of course, anything that puts more senate seats in Democratic hands is a good thing), but I think it would be particularly beneficial in terms of breaking that particular dynamic.