Republican presidential candidate, former Massachusetts Gov. Mitt Romney walks on his plane as it flies to Washington Dulles Airport for a Virginia campaign rally at The Patriot Center, George Mason University, in Fairfax, Va., Monday, Nov. 5, 2012. Photo: AP

This is a button on the back of a supporter of President Obama during a visit by former President Bill Clinton at a rally to get out the vote for President Obama in downtown Pittsburgh Monday, Nov. 5, 2012. Photo: AP

Republican vice presidential candidate, Rep. Paul Ryan, R-Wis., waves as he comes off the stage with his wife Janna, left, daughter Liza, second from left, and sons Sam and Charlie, right, during a campaign event, Monday, Nov. 5, 2012 in Reno, Nev. Photo: AP

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama addresses a rally during the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: Rocker Bruce Springsteen performs during a rally for President Barack Obama on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama addresses an audience of 18,000 during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: Secret Service agents surround U.S. President Barack Obama as he greets some of the 18,000 supporters during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama embraces some of the 18,000 supporters during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: 18,000 people fill the streets in front of the state capitol building to hear U.S. President Barack Obama address a rally during the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

US Republican presidential candidate Mitt Romney holds a rally at Lynchburg regional airport in Lynchburg, Virginia, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived for President Barack Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Emmanuel DUNAND Photo: EMMANUEL DUNAND, AFP/Getty Images

US Republican presidential candidate Mitt Romney holds a rally at Lynchburg regional airport in Lynchburg, Virginia, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived for President Barack Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Emmanuel DUNAND Photo: EMMANUEL DUNAND, AFP/Getty Images

US Republican Presidential candidate Mitt Romney walks towards his campaign plane after a rally at Lynchburg regional airport in Lynchburg, Virginia, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived for President Barack Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Emmanuel DUNAND Photo: EMMANUEL DUNAND, AFP/Getty Images

MADISON, WI - NOVEMBER 05: Supporters listen to U.S. President Barack Obama address a rally during the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: Rocker Bruce Springsteen (L) welcomes U.S. President Barack Obama to the stage during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama addresses an audience of 18,000 during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

US Republican presidential candidate Mitt Romney holds a rally at Lynchburg regional airport in Lynchburg, Virginia, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived for President Barack Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Emmanuel DUNAND Photo: EMMANUEL DUNAND, AFP/Getty Images

Singer Bruce Springsteen (C) and his wife Patti Scialfa chat with David Axelrod, US President Brack Obama's senior campaign startegist, as they board Air Force One before Obama leaves Madison, Wisconsin, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived for Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Jewel Samad Photo: JEWEL SAMAD, AFP/Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama addresses a rally during the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama addresses a rally during the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters. Photo: Chip Somodevilla, Getty Images

Supporters cheer as US President Barack Obama speaks at a campaign rally in Madison, Wisconsin, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived Monday for Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Jewel Samad Photo: JEWEL SAMAD, AFP/Getty Images

MADISON, WI - NOVEMBER 05: U.S. President Barack Obama and rocker Bruce Springsteen wave to a crowd of 18,000 people during a rally on the last day of campaigning in the general election November 5, 2012 in Madison, Wisconsin. Obama and his opponent, Republican presidential nominee and former Massachusetts Gov. Mitt Romney are stumping from one 'swing state' to the next in a last-minute rush to persuade undecided voters.

Photo: Chip Somodevilla, Getty Images

US President Barack Obama (Lower-L) speaks during a campaign rally in Madison, Wisconsin, on November 5, 2012. After a grueling 18-month battle, the final US campaign day arrived Monday for Obama and Republican rival Mitt Romney, two men on a collision course for the world's top job. The candidates have attended hundreds of rallies, fundraisers and town halls, spent literally billions on attack ads, ground games, and get out the vote efforts, and squared off in three intense debates. AFP PHOTO/Jewel Samad Photo: JEWEL SAMAD, AFP/Getty Images

Air Force One taxis as President Barack Obama arrives early morning to Madison, Wis., Monday, Nov. 5, 2012, for a campaign stop. Photo: AP

President Barack Obama salutes as he deplanes Air Force One on his early-morning arrival in Madison, Wis., Monday, Nov. 5, 2012. Photo: AP

Street sign maker Salmon Jackoyo, 32, puts the finishing touches to a hat painted with the flags of the USA and Kenya and reading "Obama for President", on the side of the road in downtown Kisumu, western Kenya Monday, Nov. 5, 2012. Many Kenyans consider President Barack Obama, the son of a white mother from Kansas and a black father from Kenya, as one of their own. Photo: AP

Supporters observe a moment of prayer before Republican presidential candidate, former Massachusetts Gov. Mitt Romney spoke at a campaign event at the Orlando Sanford International Airport, Monday, Nov. 5, 2012, in Sanford, Fla. Photo: AP

A purse with a Romney-Ryan sticker sits next to suppoters on a bleacher as Republican presidential candidate, former Massachusetts Gov. Mitt Romney spoke at a campaign event at the Orlando Sanford International Airport, Monday, Nov. 5, 2012, in Sanford, Fla. Photo: AP

A campaign worker hands out signs to crowd members before Republican presidential candidate, former Massachusetts Gov. Mitt Romney arrives to speak at a campaign event at the Orlando Sanford International Airport, Monday, Nov. 5, 2012, in Sanford, Fla. Photo: AP

FILE - In this April 27, 2012 file photo, Republican presidential candidate, former Massachusetts Gov. Mitt Romney, right, and Ohio Gov. John Kasich participate in a roundtable discussion in Westerville, Ohio. Kasich is doing what he can to help Romney win the battleground state _ and that sometimes includes holding his tongue. Photo: AP

Republican presidential candidate, former Massachusetts Gov. Mitt Romney gestures as he speaks at a Florida campaign rally at Orlando Sanford International Airport, in Sanford, Fla., Monday, Nov. 5, 2012. Photo: AP

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. Photo: AP

Republican presidential candidate, former Massachusetts Gov. Mitt Romney gives two thumbs up as he boards his campaign plane after a Florida campaign rally at Orlando Sanford International Airport, in Sanford, Fla., Monday, Nov. 5, 2012, enroute to Virginia. Photo: AP

BOSTON, MA - NOVEMBER 05: Workers set up the stage at the Boston Convention and Exhibition Center for the Mitt Romney Campaign's election night event November 5, 2012 in Boston, Massachusetts. National polls show that Romney and U.S. President Barack Obama are in a virtual dead heat in the race for the presidential election on Tuesday. Photo: Joe Raedle, Getty Images

SANFORD, FL - NOVEMBER 05: Supporters look on as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Avion Jet Center on November 5, 2012 in Sanford, Florida. With one day to go until election day, Romney is making one final push throughout swing states. Photo: Justin Sullivan, Getty Images

SANFORD, FL - NOVEMBER 05: Republican presidential candidate, former Massachusetts Gov. Mitt Romney greets supporters during a campaign rally at Avion Jet Center on November 5, 2012 in Sanford, Florida. With one day to go until election day, Romney is making one final push throughout swing states. Photo: Justin Sullivan, Getty Images

US President Barack Obama walks to his limo upon arriving in Madison, Wisconsin, on November 5, 2012. Obama and Republican rival Mitt Romney are both showing signs of exhaustion as they dart from swing state to swing state, trying to fire up enthusiasm among supporters and win over any last wavering voters before November 6 election. AFP PHOTO / Jewel Samad Photo: JEWEL SAMAD, AFP/Getty Images

US President Barack Obama disembarks from Air Force One in Madison, Wisconsin, on November 5, 2012. Obama and Republican rival Mitt Romney are both showing signs of exhaustion as they dart from swing state to swing state, trying to fire up enthusiasm among supporters and win over any last wavering voters before November 6 election. AFP PHOTO / Jewel Samad Photo: JEWEL SAMAD, AFP/Getty Images