** FILE ** Air Force Two touches down as Vice President Joseph R. Biden and his wife, Jill, arrive in Charlotte, N.C., on Tuesday, Sept. 4, 2012, for the Democratic National Convention. (AP Photo/Gerry Broome)

Photo by: Gerry Broome

** FILE ** Air Force Two touches down as Vice President Joseph R. Biden and his wife, Jill, arrive in Charlotte, N.C., on Tuesday, Sept. 4, 2012, for the Democratic National Convention. (AP Photo/Gerry Broome)