Obama's final campaign

President Barack Obama, first lady Michelle Obama embrace on stage during his final 2012 campaign event in downtown Des Moines, Iowa, Nov. 5, 2012. (AP Photo)

President Barack Obama walks on stage after being introduced by first lady Michelle Obama, not shown, during his final 2012 campaign event in downtown Des Moines, Iowa, Nov. 5, 2012. (AP Photo)

President Barack Obama speaks to supporters during his final 2012 campaign event in downtown Des Moines, Iowa, Nov. 5, 2012. (AP Photo)

President Barack Obama gestures as he speaks during his final campaign event, Nov. 5, 2012, in the downtown Des Moines, Iowa. (AP Photo)

President Barack Obama hugs first lady Michelle Obama before speaking to supporters at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama walks with first lady Michelle Obama before speaking to supporters at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama speaks to supporters during his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama waves to supporters after speaking at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama greets supporters after speaking at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama and first lady Michelle Obama acknowledge the crowd at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in the downtown Des Moines, Iowa. (AP Photo)

First lady Michelle Obama hugs her husband President Barack Obama on stage at his final campaign stop on the evening before the 2012 election in downtown Des Moines, Iowa, Nov. 6, 2012. (AP Photo)

First lady Michelle Obama cheers on her husband President Barack Obama as she joins him on stage at the end of the final 2012 campaign event in downtown Des Moines, Iowa, Nov. 6, 2012. (AP Photo)

Singer Bruce Springsteen performs prior to before President Barack Obama taking the stage at his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

Singer Bruce Springsteen greets first lady Michelle Obama after introducing her to speak at President Barack Obama's final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama and first lady Michelle Obama wave to supporters during his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama speaks to supporters during his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama speaks to supporters during his final campaign stop on the evening before the 2012 election, Nov. 5, 2012, in Des Moines, Iowa. (AP Photo)

President Barack Obama and first lady Michelle Obama wave to supporter during the final 2012 campaign event in downtown Des Moines, Iowa, Nov. 6, 2012. (AP Photo)