** FILE ** Vice President Joseph R. Biden walks out of Air Force Two upon his arrival on Oct. 11, 2012, at Blue Grass Airport in Lexington, Ky., for the vice presidential debate. (Associated Press)

Photo by: Pablo Martinez Monsivais

** FILE ** Vice President Joseph R. Biden walks out of Air Force Two upon his arrival on Oct. 11, 2012, at Blue Grass Airport in Lexington, Ky., for the vice presidential debate. (Associated Press)