Official portrait of President-elect Barack Obama on Jan. 13, 2009.
(Photo by Pete Souza)

Barack Obama teaches constitutional law at the University of Chicago in the 1990s.

Barack Obama, wife Michelle, daughters, sister, Maya and unidentified in Honolulu during Christmas 2006. On far right is Madelyn Dunham, Barack’s grandmother. Photo courtesy Barack’s half sister Maya Soetoro-Ng

President Barack Obama, First Lady Michelle Obama, and their daughters, Sasha and Malia, sit for a family portrait in the Oval Office, Dec. 11, 2011. (Official White House Photo by Pete Souza)
This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.Ê

US President Barack Obama and family arrive on stage after winning the 2012 US presidential election November 7, 2012 in Chicago, Illinois. Obama swept to re-election, forging history again by defying the dragging economic recovery and high unemployment which haunted his first term to beat Republican Mitt Romney. AFP PHOTO / Saul LOEBSAUL LOEB/AFP/Getty Images

President Barack Obama is photographed during a presidential portrait sitting for an official photo in the Oval Office, Dec. 6, 2012. (Official White House Photo by Pete Souza)

President Barack Obama winks as he is welcomed before speaking to the House Democratic Issues Conference in Cambridge, Md., Friday, Feb. 14, 2014. Opening a weekend trip to California, the president Barack Obama will offer millions in federal aid for the drought-stricken state, then hold an unusual West Coast meeting with Jordan’s King Abdullah II, a key U.S. partner in the Middle East. (AP Photo/Jacquelyn Martin)

March 7, 2015
“I was moving around trying to capture different scenes away from the stage during the event to commemorate the 50th Anniversary of Bloody Sunday and the Selma to Montgomery civil rights marches. When I glanced back towards the stage, I noticed the President and First Lady holding hands as they listened to the remarks of Rep. John Lewis. I managed to squeeze off a couple of frames before they began to applaud, and the moment was gone.” (Official White House Photo by Pete Souza)
This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.

Rally with Sen. Barack Obama, his wife Michelle and children Sasha and Malia close to the State Capitol in Des Moines, Iowa on Tuesday, May 20, 2008. (Chicago Tribune photo by Zbigniew Bzdak) ..OUTSIDE TRIBUNE CO.- NO MAGS, NO SALES, NO INTERNET, NO TV, CHICAGO OUT.. 00293862A OBama

President Barack Obama walks across the tarmac after greeting guests before boarding Air Force One at Moffett Federal Airfield in Mountain View, Calif., Thursday, Feb. 11, 2016. Obama is traveling to Los Angeles to tape an appearance on the Ellen DeGeneres Show and attend a pair of private Democratic fund raisers. (AP Photo/Pablo Martinez Monsivais)