John McCain's message machine shifted gears today -- after a week or so of offbeat efforts to annoy and exasperate Barack Obama, the Republican's campaign launched a new bid to distance himself from the titular head of his own party. A 60-second McCain television ad airing in several of this year's key battleground states seeks to both remind voters of the "maverick" image that gained him national prominence and undercut arguments that he's a President Bush clone. Indeed, the spot's third sentence offers this starkly negative assessment of the incumbent's second term: "We’re worse off than we were four years...