No other scandal in American history has had such far-reaching complexities with so few consequences as the Iran-Contra scandal that plagued presidents Ronald Reagan and George Bush in the 1980s.

During the presidency of Ulysses S. Grant, corruption was the order of the day, and cabinet members and federal judges were forced to resign to avoid impeachment. Grant prudently decided not to seek a third term. Warren G. Harding, considered by most scholars to be the worst president of all time, was spared removal from office only by his death. His wife then burned his papers to spare what was left of his reputation. Richard Nixon was not so fortunate. Once he was ordered to release tapes of conversations conducted in the Oval Office that revealed a coverup of the Watergate hotel break-in, Nixon reluctantly resigned. Bill Clinton was dogged by opponents from the point that...