Continuity of government exercisesAfter Reagan is inaugurated in 1981, Rumsfeld, and his old partner Dick Cheney, now a republican congressman from Wyoming, begin participating in the Reagan administrations's covert continuity of government exercises. Once a year, for every year during the 80s, Rumsfeld and Cheney, along with dozens of other federal officials including George H.W. Bush, are whisked away in the middle of the night to remote locations around the country simulating America's response if its governmental leadership is "decapitated" by a Soviet nuclear attack. The program circumvents the constitution and is legally questionable.
Later, the Clinton administration will abandon these exercises; however, on Sept. 11, 2001, when the nation finds itself under attack by terrorists, the plan is reactivated. While Cheney and Rumsfeld remain in secure locations in Washington, other important cabinet offices are evacuated to the same undisclosed bunkers around the country where Rumsfeld and Cheney had played out this scenario years earlier.
http://www.pbs.org/wgbh/pages/frontline/shows/pentagon/etc/cronfeld.html