President Barack Obama and Gen. Martin Dempsey, Chairman of the Joint Chiefs of Staff, attend the September 11th Observance Ceremony at the Pentagon Memorial in Arlington, Va., Sept. 11, 2014.

President Barack Obama and Gen. Martin Dempsey, Chairman of the Joint Chiefs of Staff, attend the September 11th Observance Ceremony at the Pentagon Memorial in Arlington, Va., Sept. 11, 2014.

President Barack Obama, Defense Secretary Chuck Hagel, and Gen. Martin Dempsey, Chairman of the Joint Chiefs of Staff, listen to the national anthem during the September 11th Observance Ceremony at the Pentagon Memorial in Arlington, Va., Sept. 11, 2014.

President Barack Obama, Defense Secretary Chuck Hagel, and Gen. Martin Dempsey, Chairman of the Joint Chiefs of Staff, listen to the national anthem during the September 11th Observance Ceremony at the Pentagon Memorial in Arlington, Va., Sept. 11, 2014.

President Barack Obama greets Casey Breitenbeck, White House Advance Lead, after arriving at the Turner-Fairbank Highway Research Center in McLean, Va., July 15, 2014.

President Barack Obama greets Casey Breitenbeck, White House Advance Lead, after arriving at the Turner-Fairbank Highway Research Center in McLean, Va., July 15, 2014.

June 29, 2014 "The President shares a quiet moment with his daughter Sasha during a father and daughter hike at Great Falls, Virginia." (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.

June 29, 2014
"The President shares a quiet moment with his daughter Sasha during a father and daughter hike at Great Falls, Virginia." 
(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.

President Barack Obama and Education Secretary Arne Duncan have lunch together at FireFlies in Alexandria, Va., June 10, 2014.

President Barack Obama and Education Secretary Arne Duncan have lunch together at FireFlies in Alexandria, Va., June 10, 2014.

President Barack Obama, Defense Secretary Chuck Hagel and General Martin Dempsey, Chairman of the Joint Chiefs of Staff, bow their heads as Chaplain Col. Michael Brainerd delivers the invocation during a Memorial Day ceremony at the Arlington National Cemetery Memorial Amphitheater in Arlington, Va., May 26, 2014.

President Barack Obama, Defense Secretary Chuck Hagel and General Martin Dempsey, Chairman of the Joint Chiefs of Staff, bow their heads as Chaplain Col. Michael Brainerd delivers the invocation during a Memorial Day ceremony at the Arlington National Cemetery Memorial Amphitheater in Arlington, Va., May 26, 2014.

President Barack Obama, with Maj. Gen. Jeffrey S. Buchanan, Commanding General, U.S. Army Military District of Washington, participates in a Memorial Day wreath laying at the Tomb of the Unknown Soldier at Arlington National Cemetery in Arlington, Va., May 26, 2014.

President Barack Obama, with Maj. Gen. Jeffrey S. Buchanan, Commanding General, U.S. Army Military District of Washington, participates in a Memorial Day wreath laying at the Tomb of the Unknown Soldier at Arlington National Cemetery in Arlington, Va., May 26, 2014.

President Barack Obama signs the guest book following a tour of Monticello with President François Hollande of France in Charlottesville, Va., Feb. 10, 2014.

President Barack Obama signs the guest book following a tour of Monticello with President François Hollande of France in Charlottesville, Va., Feb. 10, 2014.

President Barack Obama and President François Hollande of France tour Monticello with Leslie Bowman, President of the Thomas Jefferson Foundation, in Charlottesville, Virginia, Feb. 10, 2014.

President Barack Obama and President François Hollande of France tour Monticello with Leslie Bowman, President of the Thomas Jefferson Foundation, in Charlottesville, Virginia, Feb. 10, 2014.

President Barack Obama and President François Hollande of France tour Monticello in Charlottesville, Va., Feb. 10, 2014.

President Barack Obama and President François Hollande of France tour Monticello in Charlottesville, Va., Feb. 10, 2014.