The problem of presidential illness, disability, or succession raises serious concerns about leadership performance and the conduct of American foreign and domestic policy. Several concerns are posed by impaired leadership, including the public's right to know about a leader's health, especially in a democracy; the physician's dual role as doctor and citizen; and the implications that such limitations might pose for public policy. This problem is neither rare nor trivial.

Since 1789, forty-two men have been president of the United States. Four of them have been assassinated in office (James Garfield, William McKinley, Abraham Lincoln, and John Kennedy). Unsuccessful assassination attempts were made on several others, including Franklin Roosevelt, Harry Truman, Richard Nixon, Gerald Ford, and Ronald Reagan. Only the attempt on Reagan's life led to serious injury to the victim. Four others have died in office from natural causes (William Harrison, Zachary Taylor, Warren Harding, and Franklin Roosevelt). Nixon resigned his office. In that time, vice presidents have hardly fared better. Seven died in office (George Clinton, Elbridge Gerry, William King, Henry Wilson, Thomas Hendricks, Garrett Hobart, and James Sherman). John Calhoun and Spiro Agnew resigned. And nine left the office to assume the presidency (John Tyler, Millard Fillmore, Andrew Johnson, Chester Arthur, Theodore Roosevelt, Calvin Coolidge, Harry Truman, Lyndon Johnson, and Gerald Ford).

Dr. Herbert Abrams estimated that when George Bush was president, Vice President Dan Quayle had a 35 percent chance of becoming president, based on the twentieth-century probability of presidential mortality rates. As Dr.