President Barack Obama is flanked on stage by musicians Jay-Z, left, and Bruce Springsteen at a campaign event at Nationwide Arena, Monday, Nov. 5, 2012, in Columbus, Ohio. (AP Photo/Carolyn Kaster)

With the Wisconsin State Capitol building dome behind him, President Barack Obama speaks at a campaign event, Monday, Nov. 5, 2012, in downtown Madison, Wis. (AP Photo/Carolyn Kaster)

Crowd members hold up a sign reading "vote" as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign event at the Orlando Sanford International Airport, Monday, Nov. 5, 2012, in Sanford, Fla. (AP Photo/David Goldman)

President Barack Obama greets supporters during a campaign event near the State Capitol Building in Madison, Wis., Monday, Nov. 5, 2012. (AP Photo/Pablo Martinez Monsivais)

Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks at a Florida campaign rally at Orlando Sanford International Airport, in Sanford, Fla., Monday, Nov. 5, 2012. (AP Photo/Charles Dharapak)

President Barack Obama, accompanied by singer Bruce Springsteen, waves as he arrive at a campaign event near the State Capitol Building in Madison, Wis., Monday, Nov. 5, 2012. (AP Photo/Pablo Martinez Monsivais)

Republican presidential candidate and former Massachusetts Gov. Mitt Romney speaks at a Virginia campaign rally at Newport News International Airport, in Newport News, Va., Sunday, Nov. 4, 2012. (AP Photo/Charles Dharapak)

Republican presidential candidate, former Massachusetts Gov. Mitt Romney gestures as he leaves a Virginia campaign rally at Lynchburg Regional Airport, in Lynchburg, Va., Monday, Nov. 5, 2012. (AP Photo/Charles Dharapak)

Republican presidential candidate, former Massachusetts Gov. Mitt Romney gestures as he speaks at a Virginia campaign rally at Lynchburg Regional Airport, in Lynchburg, Va., Monday, Nov. 5, 2012. (AP Photo/Charles Dharapak)