Republican presidential candidate Mitt Romney boards his campaign plane in Moline, Ill., as he heads to Dayton, Ohio, on Monday, Oct. 29, 2012. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

Republican presidential candidate Mitt Romney boards his campaign plane in Moline, Ill., as he heads to Dayton, Ohio, on Monday, Oct. 29, 2012. (AP Photo/Charles Dharapak)