Documentary Brings Together 20 Presidential Chiefs J. Scott Applewhite / AP Photo Former Vice President Dick Cheney at the Capitol on July 17, 2012 NEW YORK - The only man to hold both jobs says in a Discovery documentary that airs Wednesday that the White House chief of staff generally has more power than the vice president. "I was speaking from an historical perspective," Dick Cheney is quick to clarify in an interview. Cheney, chief of staff under President Gerald Ford, was widely perceived as an involved and influential vice president under George W. Bush. Discovery's film, The Presidents" Gatekeepers, airs for two hours each on Wednesday and Thursday. Dozens of little-known stories about historical events big and small are told while outlining the duties of the appointed official most responsible for seeing whether a president's agenda succeeds or fails. Joshua Bolten and Rahm Emanuel discuss the terrorist threat that kept them in the White House situation room as Barack Obama was inaugurated to replace Bush. Assistant chief Larry Higby reveals that the voice-activated tape recorder that led to Richard Nixon's downfall was installed because the president was too clumsy to figure out a manual one. Lyndon Johnson's fear that he wouldn't survive a second term because of his health was a big factor in his decision not to run in 1968, Marvin Watson explains; Johnson died two days after a second term would have ended. All 20 of the presidential aides sought for interviews agreed to participate, along with former presidents Jimmy Carter and George H.W. Bush, said filmmaker Jules Naudet, who made the documentary with his brother Gedeon and executive producer Chris Whipple. They enlisted former Ford aide David Hume Kennerly to win the cooperation of Cheney, who sat for seven hours of interviews, and his one-time boss Donald Rumsfeld. When former Ronald Reagan and George H.W. Bush aide James Baker, considered the "gold standard" of modern chiefs, became the third interview, the rest fell into place. "The chiefs love the fact that for the first time, it's about them and not about their presidents," Naudet said. To a man, they agreed it was a meat grinder of a job, with constant pressure and endless hours. The typical chief lasts less than two years. It's miserable to go through, Emanuel concludes, but every chief would do it again if asked. Before being brought down like his boss in Watergate, H.R. Haldeman set the modern standard for a strong, centralized authority at the White House, said Cheney, a low-level Nixon aide then in his 20s. "He spent a lot of time thinking about it," Cheney said, "and quite frankly I think most of us subsequently, without ever saying that's what we were doing, sort of gravitated to (his) model." Ford initially supported a "spokes in a wheel" management theory where several aides report directly to the president. That may have worked in a congressional office, but not in the White House, Cheney said. Somebody needs to set the president's schedule, make certain he sees all the necessary correspondence and has everything on hand when a decision is to be made. "You have to have somebody disciplined running the calendar because the president's time is the most valuable thing there is," Cheney said. If you don't have anybody in charge, none of that happens. Then there are the duties no one can anticipate: When Ford lost his voice in the last days of the 1976 campaign, it was Cheney who had to read the president's concession over the phone to Carter the morning after the election. "It was sort of the nadir of my career," he said. Ford later poked fun at Cheney for accepting the vice presidential nomination, saying his time in that job under Nixon was the worst eight months of his life. Cheney said Bush promised "that he wanted me to be an important part of the team, not just doing funerals and fundraisers. He kept his word. The chiefs share a bond that often transcends politics. Bolten invited many of the former chiefs, including Cheney, to an advisory lunch with Emanuel shortly before Obama took office. The documentary doesn't follow chronological order, and it darts between serious stories like Andrew Card's recollections of the Sept. 11 terrorist attacks and George H.W. Bush's mock "award" to aides who fell asleep in meetings. The idea was to reach beyond political junkies, said Whipple, a former ABC News producer who interviewed each chief. "What we planned to do from the very beginning was to imagine that the chiefs of staff were there with you, sharing a cup of coffee or a glass of wine and telling you their stories," Naudet said. We didn't want it to feel like a traditional documentary. The Naudet brothers are known best for 9/11, the gripping documentary they made after unexpectedly finding themselves in the center of the attacks while filming a piece on firefighters that morning. It feels a little odd to them that The Presidents" Gatekeepers premieres exactly 12 years after that awful day. "I feel like I'm always brought back to that date," he said. It always follows us around.