BOB: The attempts by late FBI Director J. Edgar Hoover to discredit Dr. Martin Luther King Jr. were an ugly and well-documented chapter in American history.  The FBI wiretapped, hounded, and tried to peddle sordid details of King’s sex life to the press. Perhaps the most monstrous example was the so-called “suicide letter.” The typewritten blackmail note -- 'til now available in heavily redacted form -- is a study in blackmail wrapped in righteous indignation, threatening to expose King’s sexual activities to the world unless he did the "one thing left” to escape shame.  That “thing” is widely interpreted to mean suicide. Now, Yale professor Beverly Gage has discovered a previously unseen, redaction-free version of the letter. In this week’s New York Times Magazine, she analyzes the elaborate dirty trick and wonders aloud how the contemporary media would have dealt with the dirt itself. In her article Gage featured some of the most hate-filled, previously-redacted, sections of the letter…

Gage: "No person can overcome facts. Not even a fraud like yourself. Lend your sexually psychotic ear to the enclosure. You will find yourself in all your dirt, filth, evil and moronic talk exposed on the record for all time."

BOB: So he sounds upset.

GAGE: A little bit. The letter was sent by the FBI to King as an anonymous note. And it was accompanied by an audio tape that has not been released that was based on bugs that had been places in King's hotel rooms while he was travelling. Really as a threat of exposure.

BOB: Who actually wrote it.

GAGE: The letter seems to have been written by a man named William Sullivan who was one of the Hoover's deputies. What's less clear is exactly what role Hoover himself played in all of this. This letter is in fact in Hoover's official and confidential files. Which he kept in his own office. But we don't have anything with Hoover's signature. He didn't sign off saying...'terrific! send the tapes to King! send that letter to King.'

BOB: Let's go back a bit to when and why the FBI got on to King in the first place. Where did this all begin?

GAGE: The FBI had been following Civil Rights activists of various sorts as early as the 1920s. Black activists, people on the left, they hadn't actually been paying a lot of attention to King himself until about 1961 when they learned that one of his very close white advisers, a man named Stanley Levison had actually been a pretty important figure in the Communist Party in the 1950s. They found out about Levison's growing relationship with King. And they found that in the Cold War context, very alarming.

BOB: So civil rights troublemaker and fairly high-level commie. Just the sort of thing to get the attention of J. Edgar Hoover.

GAGE: Right. The FBI had this theory that Stanley Levison might have broken with the Communist Party in order to then cozy up to Martin Luther King deliberately, and act as a Soviet spy. So they had a sort of elaborate theory about all of this. Not based on a lot of evidence. But that became a sort of national security logic for wiretapping Stanley Levison. And in turn that became a sort of cascading series of invasions of privacy which by 1963 they had begun to bug and wiretap King himself.

BOB: And for his part, Dr. King took on the FBI and questioned its tactics. And it's seriousness about enforcing federal law in the Deep South.

GAGE: That's right. King saw the FBI as being sort of in collusion with Southern law enforcement. Not protecting Civil Rights workers. And he'd come out and said this publicly. Which was the very thing that J. Edgar Hoover hated most in the world. And that was going to bring his attention to you more than just about anything that you could do. And so by November 18, 1964, Hoover held a very long press conference and one of the things that he said at that press conference was that King was quote: "the most notorious liar in the country.'

BOB: That was the public attack on King. In the meantime the FBI was using the fruits of its wiretapping campaign to try to leak material to the press about Dr. King's let's just say libertine behavior. And the press, this was the 60s -- not 2014. Said 'eh...no.'

GAGE: No one would bite. There was a different kind of culture around exposing the sexual private lives of public figures. John Kennedy's extramarital affairs are now very famous to us but they were largely unknown at the time, though they were an open secret in Washington. I think a particularly in King's case there was a sense that this wasn't just about exposing say, the hypocrisy of someone who is supposed to be a moral leader but is in fact not being faithful to his wife. I think many reporters understood that this was an attempt to take down really an entire movement and to remove King as an influential political figure, and resisted it. For that reason. And then I think finally reporters in the 1960s were probably quite afraid of the FBI. The FBI was very well known to take punitive action against reporters who printed things that the FBI did not like. You would certainly be cut out of these sort of FBI press-release favored reporters' circle. But you in fact might yourself become a FBI target. So the combination of these things I think led to a much more caution press in that moment and one that didn't move forward with these stories.

BOB: You know I'm wondering about the convergence of this sort of zealotry with the technical capabilities that the intelligence apparatus now has to scoop all this information up not just about a civil rights leader, but you and me. They're listening to all of us. Are they not?

GAGE: There seems to a real consensus in Washington and elsewhere that what happened to Martin Luther Kind and what the FBI was doing to Martin Luther Kind was a bad thing. The current FBI director actually says that he keeps a copy of the wiretap request to wiretap Martin Luther Kind on his desk as a reminder about internal overconfidence or sort of the zealotry can in fact lead to. That said, I think there are a couple of cautionary tales to come out of this. And the first one is that if intelligence agencies have a lot of detailed information about people's personal lives, that there's a temptation to use it to carry out some sort of political or personal vendetta, as we saw happen in Martin Luther King's case. And I think it's also a useful reminder that often though we are having these very passionate debates, we just don't know what's going on.

BOB: Beverly, that you so much.

GAGE: Thank you.

BOB: Beverley Gage is a Professor of American History at Yale University. And the author of 'What an uncensored letter to MLK Reveals' in Sunday's New York Times Magazine.