**FILE** President Obama walks across the South Lawn of the White House after returning from Camp David in Washington on Aug. 4, 2013, his 52nd birthday . (Associated Press)
President Barack Obama shares a humorous moment with a group of doctors from around the country in the Oval Office, Oct. 5, 2009, prior to a health insurance reform event at the White House.
(Official White House Photo by Pete Souza)
President Barack Obama waves to the media as he walks on the South Lawn of the White House in Washington after returning on Marine One from Camp David, Md., where he spent his birthday Sunday, Aug. 4, 2013. (AP Photo/Jacquelyn Martin)