No, Richard Nixon did not call Timothy Leary “the most dangerous man in America”
At least there’s no evidence that he did.

Here we go again.
Showtime just released My Psychedelic Love Story, an engaging documentary about Joanna Harcourt-Smith, the rich and beautiful young girlfriend of Timothy Leary, who tripped around the world with the irrepressible Leary after he was smuggled out of a a minimum-security prison in California in 1970.
For those of you too young to remember, Leary was a Harvard psychology professor who became a hero of the 1960s counterculture and an evangelist for LSD who exhorted his followers to “turn on, tune in and drop out.”

There’s lots more to say about Leary, but best left unsaid is claim that President Richard M. Nixon called him “the most dangerous man in America.” There’s no evidence that Nixon ever said it.
Predictably, though, critics and reporters reviewing the film in The Wall Street Journal, The Guardian, Fast Company and The San Francisco Chronicle pulled out the quote as a shorthand way to describe Leary. It’s mentioned a couple of times in the film. It was also cited in The New York Times obituary of Harcourt-Smith, who died in November. The quote also appears in The Times’ obit of Leary, who died in 1996.
But, again, there’s no evidence — other than the 1996 Times obit — that Nixon ever said it.
When I began writing about psychedelics a couple of years, I wanted to use the Nixon quote. I figured I’d check it out. I dug around a bit. I couldn’t find an original source.
A Google search for “Timothy Leary ‘the most dangerous man in America’” turns up 27,000 results. Many refer to a 2018 book by Bill Minutaglio and Steven L. Davis called The Most Dangerous Man in America: Timothy Leary, Richard Nixon and the Hunt for the Fugitive King of LSD. It’s a rollicking read, covering the crazy period during which Leary and Harcourt-Smith traveled through Switzerland, Algeria and Afghanistan, with federal agents in pursuit.

But the title!
The authors are diligent researchers so, by email, I asked Davis about the original source for the quote. Did Nixon ever say it, I asked?
He replied:
Man oh man did we ever try to track down the original citation for it. The quote seems nearly as much a matter of urban legend (possibly invented by Leary) as it is a documented fact — but then, in the end, we decided to take the paper of record, The New York Times, at its word.
He added that
as a book title it was too delicious to resist and the New York Times provided the necessary backstop — Nixon’s actions in pursuing Leary made it clear to me that, even if he didn’t literally call Leary “the most dangerous man in America,” the fervor with which he and his administration pursued Leary — which included the largest bail ever announced for an American citizen — made it clear that the quote was, at least, largely true in spirit.
I also came across a 2017 blogpost from a writer named Robert Malone who had done his own search. He couldn’t find an original source either. It remains possible, of course, that Nixon said it, but Malone concludes:
…I don’t think it happened. I’m happy to be proved wrong. Take it as a challenge if you like — present the evidence.
I emailed Malone to see if his blogpost had drawn a response. “Nobody who’s read my post has tried to offer any possible sources for the quote,” he told me. Nixon did say that drug abuse was “public enemy number one” — it’s online here — but that’s not the same thing.
So there you have it. Does it matter? Yes, because facts matter.
The Nixon quote (or non-quote), meantime, raises a different question: Was Leary dangerous and, if so, how? He was certainly careless in the way that he talked about LSD, downplaying its risks. Arguably, though, as we learn more about the therapeutic and spiritual benefits of psychedelics, the bigger danger posed by Leary may be that he grasped the world-changing potential of these chemicals: When used carefully, it appears, psychedelics connect people to one another and to the planet that we share. That may have been what riled up the authorities. The risks of drugs to those who used them was one thing; the counterculture’s threat to the status quo was quite another.