The resignation of Pope Benedict XVI and the issue it raises of how his successor deals with a living ex-pope has touched off a heated debate among presidential historians about how American presidents deal with their predecessors. Here are some examples.
"Harry Truman said Eisenhower pulled rank on him whenever he asked Ike about his foreign policy," said David McCullough. "He told Truman he shouldn't have fired Gen. MacArthur and even refused to tell him what Mamie's Secret Service code name was."
Eisenhower, in turn, complained that President Kennedy wouldn't listen to him when he warned that Khrushchev was preparing to send nuclear missiles to Cuba, and that Bobby Kennedy instructed White House switchboard operators not to accept his calls, according to Stephen Ambrose.
"What are his powers and what is he called?" Doris Kearns Goodwin asked. "Lyndon Johnson always insisted that I call him Mr. President, but everybody knew he was just a Texas rancher with no power who couldn't persuade Richard Nixon to change the name of the Lincoln Bedroom to the LBJ Bedroom."
And Nixon insisted during his exile in San Clemente that he was still entitled to top-secret security briefings, but told Ambrose that Henry Kissinger spoke only German during his briefings, and that President Ford wouldn't give Bebe Rebozo his private telephone number.
Ford, meanwhile, said Nixon never even thanked him for pardoning him after Watergate, and was unhappy that Jimmy Carter made him and Betty fly commercial instead of taking Air Force One back to Grand Rapids, according to David Gergen.
Carter, in turn, told Douglas Brinkley that Ronald Reagan wouldn't let him and Rosalyn live in Blair House until their house was remodeled in Plains, and refused to order the Department of Agriculture to raise federal subsidies for peanut farmers.
And according to Lou Cannon, Reagan bitterly resented the fact that his vice president and successor, George H. W. Bush, wouldn't allow "The Gipper" and other Reagan films to be shown in the White House movie theater, and that he hurt California farmers by taking broccoli off the menu at the White House Mess.
George H. W. Bush, now the oldest of four living ex-president, always felt Reagan contributed to his image of being out of touch with ordinary people by not showing him how to read a supermarket scanner, said Richard Reeves. "He also blamed Reagan for telling him nobody would notice if he decided to contradict his famous 'Read my lips; no new taxes' pledge," said Reeves.
Bill Clinton, after surviving his impeachment in the wake of the Monica Lewinsky scandal, told David Maraniss that Bush 41 rejected his request to sleep in the Lincoln Bedroom whenever he returned to Washington, with no questions asked about who he brought with him, and told him to have Hillary stop calling him at three o'clock in the morning.
Finally, George W. Bush revealed to Bob Woodward that Clinton asked him and Dick Cheney to accompany 100,000 troops to Iraq "so you can finish what you started," and that he turned down Bush's request to be appointed ambassador to Great Britain "because you don't speak the language."
So what will Barack Obama tell his successor? "If it's a Republican, I'm sure he'll claim that he saved the country from Joe Biden," said Jules Witcover.
Editor's note: This post is satirical.