'The Presidents' Gatekeepers' Exclusive: Tear Down That Wall!

For the first time ever, all 20 living White House Chiefs of Staff come together to share their previously untold stories on Discovery's "The Presidents' Gatekeepers." The special spans nine administrations and 50 years. Considered the second most powerful – and the toughest – job in Washington, D.C., the White House Chief of Staff is the person the president counts on to transform his agenda into reality.