President Barack Obama walks out of Blair House in Washington, Thursday, Dec. 13, 2012, before crossing Pennsylvania Avenue and returning to the White House after attending a holiday party for the National Security Council. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

President Barack Obama walks out of Blair House in Washington, Thursday, Dec. 13, 2012, before crossing Pennsylvania Avenue and returning to the White House after attending a holiday party for the National Security Council. (AP Photo/Charles Dharapak)