President Nixon’s obsession with “the whole Bay of Pigs thing” has intrigued historians, journalists and conspiracy theorists. A largely overlooked tape provides answers.

The Washington Post dubbed it “the smoking gun tape.” It was the recording that doomed the presidency of Richard Nixon. The transcript of a conversation that took place on June 23, 1972, when made public by Supreme Court order in July 1974, became the climactic revelation of the Watergate affair, proving beyond all doubt that Nixon used CIA director Richard Helms to suborn the FBI’s investigation of the Watergate burglars.

Fifty years after the botched break-in that transformed American politics, the gangsterly dialogue of the smoking gun tape is less shocking than Trumpian. Blackmail as a mode of White House politics? President 45 had nothing on President 37.

“We protected Helms from one hell of a lot of things,” Nixon growled on the tape. “You open that scab there’s a hell of a lot of things, and we just feel that it would be very detrimental to have this thing go any further. This involves these Cubans, [ex-CIA man and Watergate burglar Howard] Hunt, and a lot of hanky-panky that we have nothing to do with ourselves.”

Nixon advised chief of staff H.R. Haldeman on how to get the CIA director to kill the FBI’s probe.

“Say, ‘Look, the problem is that this will open the whole, the whole Bay of Pigs thing, and the President just feels that, ah, without going into the details … don’t, don’t lie to them to the extent to say there is no involvement, but just say this is sort of a comedy of errors, bizarre, without getting into it, the President believes that it is going to open the whole Bay of Pigs thing up again.’”

The June 23 tape was incontrovertible evidence that Nixon had obstructed justice. The last vestige of support for Nixon on Capitol Hill evaporated. Two weeks later, on Aug. 8, 1974, Nixon resigned.