US President Barack Obama celebrates after delivering his acceptance speech in Chicago on November 7, 2012.

President Barack Obama speaks at his election night party November 7, 2012, in Chicago, Illinois.

President Barack Obama walks on stage with first lady Michelle Obama and daughters Malia and Sasha at his election night party November 7, 2012, in Chicago, Illinois.

President Barack Obama waves as he walks on stage with first lady Michelle Obama and daughters Malia and Sasha at his election night party November 7, 2012, in Chicago, Illinois.

Republican presidential candidate Mitt Romney waves to supporters before conceding at his election night rally, November 7, 2012, in Boston, Massachusetts.

A supporter reacts to voting results displayed on a TV screen during Republican presidential candidate Mitt Romney's election night rally in Boston, Massachusetts, November 7, 2012.

Republican presidential candidate Mitt Romney and his wife Ann stand on the stage with Republican vice presidential candidate Paul Ryan,and his wife Janna during his election night rally, November 7, 2012, in Boston, Massachusetts.

Supporters of U.S. President Barack Obama cheer during his election night rally in Chicago, November 6, 2012.

Arizona Democrats celebrate as President Barack Obama is declared the winner of the presidential race at a Democratic Party gathering in Tucson, Arizona, Tuesday, Nov. 6, 2012.

A woman takes a photo of the Empire State Building that is lit up in blue, the color of the Democrat Party, after Barack Obama was projected to win the U.S presidential election in New York, Nov. 6, 2012.

Supporters of President Barack Obama react to favorable media projections at the McCormick Place during an election night watch party in Chicago, Tuesday, Nov. 6, 2012.

People pose with a picture of President Barack Obama during the Election Night Party 2012 following the U.S. Presidential Election, at the Intercontinental Hotel in Madrid, Spain.

Democrats celebrate reports that President Barack Obama won the election at the Ohio Democratic party election night celebration early Wednesday, Nov. 7, 2012, in Columbus, Ohio.

Ryan Charchian, 18, of New York, hugs Allie Rapa, 19, of New York after news reports projected President Barack Obama to win a second term as they celebrated in New York, Nov. 6, 2012.

People react as a television promoter announce results of the United States elections during a Presidential Election party hosted by the United States embassy and German Telekom in Berlin, Germany.

Guests look at early projections for votes for the President Barack Obama and Republican presidential candidate Mitt Romney during the Presidential Election party at the U.S. Embassy in London, England.