President Barack Obama talks with Vice President Joe Biden before boarding Air Force One at Pittsburgh International Airport prior to departure from Pittsburgh, Pa., April 16, 2014. President Obama and Vice President Biden were in Pennsylvania to tour the Community College of Allegheny County West Hills Center and to speak on the importance of jobs-driven skills training.

President Barack Obama talks with Vice President Joe Biden before boarding Air Force One at Pittsburgh International Airport prior to departure from Pittsburgh, Pa., April 16, 2014. President Obama and Vice President Biden were in Pennsylvania to tour the Community College of Allegheny County West Hills Center and to speak on the importance of jobs-driven skills training.

President Barack Obama signs hard hats and other items after delivering remarks at the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

President Barack Obama signs hard hats and other items after delivering remarks at the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

President Barack Obama waits backstage prior to delivering remarks about the retirement policies highlighted in the State of the Union address, at the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

President Barack Obama waits backstage prior to delivering remarks about the retirement policies highlighted in the State of the Union address, at the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

President Barack Obama tours the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

President Barack Obama tours the United States Steel Corporation Irvin Plant in West Mifflin, Penn., Jan. 29, 2014.

Sept. 2, 2012 "David Lienemann made this unusual photo as staff held flashlights so the Vice President could see as he signed autographs backstage at West York Area High School in York, Pa."

Sept. 2, 2012
"David Lienemann made this unusual photo as staff held flashlights so the Vice President could see as he signed autographs backstage at West York Area High School in York, Pa."

March 17, 2012 "David Lienemann made this action photograph of Vice President Joe Biden and his security detail literally running during the St. Patrick’s Day Parade in Pittsburgh, Pa."

March 17, 2012
"David Lienemann made this action photograph of Vice President Joe Biden and his security detail literally running during the St. Patrick's Day Parade in Pittsburgh, Pa."

President Barack Obama says goodbye to students after a visit to the Yeadon Regional Head Start Center in Yeadon, Pa., Nov. 8, 2011.

President Barack Obama says goodbye to students after a visit to the Yeadon Regional Head Start Center in Yeadon, Pa., Nov. 8, 2011.

President Barack Obama reads a document while en route to Pittsburgh International Airport in Pittsburgh, Pa., Oct. 11, 2011.

President Barack Obama reads a document while en route to Pittsburgh International Airport in Pittsburgh, Pa., Oct. 11, 2011.

President Barack Obama talks with Principal Deputy Press Secretary Josh Earnest, left, and National Economic Council Director Gene Sperling aboard Air Force One on the flight to Pittsburgh, Pa., Oct. 11, 2011.

President Barack Obama talks with Principal Deputy Press Secretary Josh Earnest, left, and National Economic Council Director Gene Sperling aboard Air Force One on the flight to Pittsburgh, Pa., Oct. 11, 2011.

President Barack Obama and First Lady Michelle Obama visit the crash site following a ceremony at the Flight 93 National Memorial in Shanksville, Pa., on the tenth anniversary of the 9/11 attacks against the United States, Sunday, Sept. 11, 2011.

President Barack Obama and First Lady Michelle Obama visit the crash site following a ceremony at the Flight 93 National Memorial in Shanksville, Pa., on the tenth anniversary of the 9/11 attacks against the United States, Sunday, Sept. 11, 2011.