Exactly when did it become conventional wisdom that Clarence Harmon would be one-term city mayor? Was it when he fired Michael Jones, his effective deputy mayor for development? Was it when Hizzoner refused to give Cornell Haynes Jr., a.k.a. Nelly, a proclamation, protesting that the chart-topping, St. Louis-promoting rapper's lyrics were offensive? Harmon, the anti-Freeman Bosley Jr. candidate in 1997, never built much of a base, so when he faced strong challengers four years later, the mayor's election loss seemed a foregone conclusion. Harmon couldn't even muster a respectable showing, getting just 5 percent of the Democratic-primary vote in a field that included Bosley, Aldermanic President Francis Slay Jr. and school-board member Bill Haas. Harmon's political obit seemed eerily foretold on primary day, when Post readers saw a death notice for a "Clarence A. Harmon." Pure coincidence, really: This Clarence, unlike the mayor, was a 32nd-degree Mason, veteran and Illinois resident. But the end result was similar -- both men, it seems, were goners.