Barack Obama went into the garage Thursday morning for an overhaul, a ring-and-valve job at a minimum, and the mechanics will have him ready for the next debate Oct. 11 at tiny Centre College in Kentucky. Mitt Romney can’t count on getting a weak, confused and bumbling opponent next time. But the messiah’s honeyed words no longer charm. The novelty of voting for the first black president to assuage white liberal guilt has just about worn off. The Obama dilemma is that he must go on the offensive, whether presidential or not. But defending the indefensible, as he learned Wednesday night, is a fool’s errand.