Republican presidential candidate Mitt Romney speaks at a campaign rally at Shady Brook Farm in Morrisville, Pa., on Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Fireworks go off as Republican presidential candidate, former Massachusetts Gov. Mitt Romney finishes his speech on stage at a campaign event at Shady Brook Farm, Sunday, Nov. 4, 2012, in Morrisville, Pa. (AP Photo/David Goldman)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney and wife Ann wave from their bus as they arrive at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney leaves the stage as fireworks explode behind him at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney and Ann Romney arrive on their campaign bus at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate, former Massachusetts Gov. Mitt Romney wavs to the crowd after speaking at a campaign event at Shady Brook Farm, Sunday, Nov. 4, 2012, in Morrisville, Pa. (AP Photo/David Goldman)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney speaks at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Supporters wave flags as Republican presidential candidate and former Massachusetts Gov. Mitt Romney speaks at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney and his wife Ann Romney take the stage at a Pennsylvania campaign rally at Shady Brook Farm, in Morrisville, Pa., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney meets with Bishop David M. O'Connell of Trenton, N.J., as he steps off his campaign plane in Philadelphia, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney walks out on stage as he campaigns at Iowa Events Center, in Des Moines, Iowa, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney greets supporters as he campaigns at the International Exposition Center in Cleveland, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney poses with children wearing shirts which spell out "Romney" as he campaigns at the Iowa Events Center, in Des Moines, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney and Ann Romney take the stage as they campaign at the International Exposition Center in Cleveland, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Ann Romney waves as she leaves the stage after introducing Republican presidential candidate and former Massachusetts Gov. Mitt Romney at a campaign rally at the International Exposition Center in Cleveland, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney holds his wife Ann's hand as they arrive to campaign at the International Exposition Center in Cleveland, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney emerges from backstage to campaign at Iowa Events Center, in Des Moines, Iowa, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)
Crowd members watch as Republican presidential candidate, former Massachusetts Gov. Mitt Romney, speaks during a campaign event at the International Exposition, Sunday, Nov. 4, 2012, in Cleveland. (AP Photo/David Goldman)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney stands with Ann Romney on their plane after they campaigned at the International Exposition Center in Cleveland, Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)