Andrew Sullivan has posted an interesting video from the Democratic National Committee on several of the notable flip-flops by Mitt Romney. Remarkably, it was obviously made before the most recent exposure of his flip — or is it flop — on undocumented immigrants who are long-time residents of the United States. The DNC’s tactic here follows the time-honored tradition (mostly by Republicans, I think) of defining your opponent before he or she can establish a different view. It could also play a significant role in Iowa where Newt Gingrich’s recent effort to state his version of a humane policy may cause him some difficulty.