Under the Supreme Court’s recent ruling on presidential immunity, could President Richard M. Nixon have legally ordered his Plumbers to burgle the office of Daniel Ellsberg’s psychiatrist? Might they all have gotten away with it? It certainly looks that way to me, and I have a particular interest in this matter. As a young lawyer in the Los Angeles District Attorney’s Office in 1971, I oversaw the burglary indictment of senior White House officials and White House operatives for...