President Barack Obama and First lady Michelle Obama joined by their children Sasha, left, and Malia walks across the stage after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/David Goldman) President Barack Obama applauds before his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky) From left, Michelle Obama's mother Marian, Malia and Sasha Obama, their mother Michelle and Dr. Jill Biden, wife of Vice President Biden, listen to President Barack Obama at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) Margaret Munro, of Richland, Wash., listens to the televised 2012 Democratic National Convention Thursday Sept. 6, 2012 at the Plumbers and Steamfitters Local Union Hall 598 in Pasco, Wash. Munro wears a cloth wrap with a portrait of President Barack Obama made by her friend Fatima Traore’s mother who lives in Mali in Africa. (AP Photo/The Tri-City Herald,Paul T. Erickson ) LOCAL TV OUT; LOCAL RADIO OUT KONA First lady Michelle Obama, left, Vice President Joe Biden, Dr. Jill Biden, and President Barack Obama hug each other after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charles Dharapak) First lady Michelle Obama, Vice President Biden's wife Dr. Jill Biden, and President Barack Obama wave after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) President Barack Obama and his daughter Malia wave after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charles Dharapak) President Barack Obama and his daughter Malia wave after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charles Dharapak) President Barack Obama, first lady Michelle Obama, their children Malia and Sasha, and Vice President Joe Biden and his wife Jill Biden, wave on stage on the final day of the Democratic National Convention in Charlotte, N.C., Thursday, Sept. 6, 2012. (AP Photo/Pablo Martinez Monsivais) President Barack Obama is joined on stage by first lady Michelle Obama, left, their children Malia and Sasha, right, on the final day of the Democratic National Convention in Charlotte, N.C., Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) President Barack Obama and his family and Vice President Joe Biden and his family celebrate their nominations as the confetti falls at the conclusion of the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Carolyn Kaster) President Barack Obama waves after his speech at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/David Goldman) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Carolyn Kaster) Vice President Joe Biden and President Barack Obama wave to the delegates after President Obama's speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charles Dharapak) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charles Dharapak) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/David Goldman) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) President Barack Obama speaks at the Democratic National Convention in Charlotte, N.C., Thursday, Sept. 6, 2012. (AP Photo/Pablo Martinez Monsivais) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite) President Barack Obama speaks to delegates at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite) President Barack Obama addresses the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/David Goldman) President Barack Obama waves to candidates at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky) President Barack Obama, left, is joined on stage by first lady Michelle Obama, left, their children Sasha and Malia, right, on the final day of the Democratic National Convention in Charlotte, N.C., Thursday, Sept. 6, 2012.(AP Photo/Charles Dharapak) President Barack Obama waves after his speech at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Jae C. Hong) President Barack Obama stands on stage after addressing the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite) Vice President Joe Biden and President Barack Obama wave to the delegates at the conclusion of Presdident Obama's speech at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite)