Republican presidential candidate and former Massachusetts Gov. Mitt Romney laughs as he talks with senior advisers on his campaign plane en route to Denver, Monday, Oct. 1, 2012. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

Republican presidential candidate and former Massachusetts Gov. Mitt Romney laughs as he talks with senior advisers on his campaign plane en route to Denver, Monday, Oct. 1, 2012. (AP Photo/Charles Dharapak)