Harvard: where old mayors get put out to stud?If those who can’t do, teach, does it also follow that those who can’t win a second re-election bid, fellow? For the answer, see Greg Nickels.Harvard University today confirmed the rumor that former Seattle Mayor Greg Nickels, the man who famously left college before graduating for a career in politics, will return to academia as a fellow at the John F. Kennedy School of Government’s Institute of Politics. Nickels will spend the spring of 2010 auditing classes, with carte blanche to pursue whatever line of academic inquiry he chooses. He’ll lead discussion groups with undergrads, where his role in crafting the U.S. Mayor’s Climate Control Agreement will undoubtedly be a topic of choice. (The announcement of the fellowships identified Nickels as the agreement’s author, so it’s safe to assume that this particular accomplishment weighed heavily in his selection.)Of course, there are other reasons to accept the gig, specifically, the chance to renew a rivalry with his onetime chief political antagonist. Waiting for Nickels, presumably ready to engage in one gnarly game of quad lacrosse, is former city council member Peter Steinbrueck. Last spring, Steinbrueck chose a fellowship at Harvard’s Graduate School of Design over the chance to challenge Nickels in last year’s mayoral election. Steinbrueck is studying sustainable development, and he’ll no doubt have some ideas to bounce off Nickels once he arrives. The storm clouds, they do gather.