** FILE ** In these Aug. 2012 photos, President Obama and Republican presidential candidate, former Massachusetts Gov. Mitt Romney, right, campaign. The challenge for Obama and Romney is how to lay claim to the small but mightily important swath of the electorate, the undecided likely voter. (AP Photos)

Photo by: Mary Altaffer, Evan Vucci

** FILE ** In these Aug. 2012 photos, President Obama and Republican presidential candidate, former Massachusetts Gov. Mitt Romney, right, campaign. The challenge for Obama and Romney is how to lay claim to the small but mightily important swath of the electorate, the undecided likely voter. (AP Photos)