New Jersey Gov. Chris Christie's confirmation today that he would not seek the 2012 Republican presidential nomination was a relief to Mitt Romney, who stood to lose out most if Christie entered the race. But as Jon Stewart explained on tonight's Daily Show, Romney's history of switching positions on key issues stands in his way more than a fat guy from Jersey ever could: "Mitt Romney has a bit of a problem... to win the Republican nomination, he has to convince Republican voters he's not actually Mitt Romney."