Sophisticates, cynics, and moralists of all stripes long have held that there is not “a dime’s worth of difference” between the Republican Party and the Democratic one, and that elections might as well be settled by a toss of that very same dime. But the talk-show host or fringe activist who assumes such a flippant attitude toward partisan politics might check his beliefs against the events of the past week. Every day brings news that would be utterly different had Mitt Romney won the 2012 election.