Ajamu Baraka, professorial with kind eyes, was an accomplished human-rights activist before joining the Green Party ticket as Jill Stein’s running mate.

But the two leftist candidates—due for a mainstream close-up in a CNN town hall on Wednesday—also have engaged with some fringe thinkers and conspiracy theories . Baraka, especially, has an accomplished résumé in this field.

Earlier this year, the former executive director of the U.S. Human Rights Network had his work featured in a book edited by accused Holocaust denier (“the Holocaust controversy was a legitimate topic of historical debate”) and self-described 9/11 truther Kevin Barrett. The book, Another French False Flag? Bloody Tracks from Paris to San Bernardino, featured the likes of Jewishness-loathing Gilad Atzmon and Ken O’Keefe, who once made a YouTube video explaining how “Hitler was right.”

Baraka, though, says that he was not aware of Barrett’s views prior to having his work appear in the book.

“When Kevin Barrett, someone who has interviewed me in the past, contacted me to ask if he could include my piece in a compilation on the Paris Attacks, I didn’t see any problem with it,” Baraka said in a statement to Gawker in which he stridently disavowed Holocaust denial. “I didn’t inquire as to the other authors and don’t know much about some of them or their positions on various issues. I stand by everything I wrote in that article and would be happy to discuss the details.”

Neither he nor the ticket’s spokesman responded to requests for further comment from The Daily Beast.

The essay in question was first published on CounterPunch, a site that once ran a 12,000-word investigation on Israel’s role in the 9/11 attacks and bills itself as the “Fearless Voice of the American Left.” In the essay, Baraka makes an argument that the November terror attacks in Paris were an example of “The White Lives Matter Movement” played out on an international stage.

“In fact some states—like the United States—proudly claim their ‘exceptionality,’ meaning impunity from international norms, as a self-evident natural right,” Baraka writes.

“And in that sense, while the victims of the violence in Paris may have been innocent, France was not. French crimes against Arabs, Muslims and Africans are ever-present in the historical memory and discourse of many members of those populations living in France. Those memories, the systemic discrimination experienced by many Muslims and the collaboration of French authorities with the U.S. and others that gave aid and logistical support to extremist elements in Syria and turned their backs while their citizens traveled to Syria to topple President Assad, became the toxic mix that resulted in the blowback on November 13.

“Although a number of the dead in Paris are young Arabs, Muslims and Africans, in the global popular imagination, France, like the U.S. (even under a Black president), is still white.”

This wasn’t Baraka’s only engagement with Barrett, or flirtation with a false flag ideology.

The two scholars of revisionist history appeared together more than once on Barrett’s Truth Jihad radio show. In one broadcast on July 19, 2014, the topic of discussion was the recently downed Malaysia Airlines flight 17, which was reportedly taken down by pro-Russian insurgents. At least, that’s what American intelligence sources would have you believe.

“What do you think of this plane—Malaysian plane shootdown?” Barrett asks. “The U.S. media is putting out the possibilities of this being done by the Russians or by the pro-Russian Ukrainians, but President Putin’s plane was flying through there shortly before this plane was shot down—it looks like Putin’s plane may have been targeted. If so, obviously that wouldn’t have been done by the Russians or pro-Russian separatists quote unquote, that would have been done by the Kiev Zio-Nazi government. Which is what it is—these Zionist Jewish oligarchs, billionaire criminal dons, are funding Nazi street thugs. These are the people who overthrew the legitimate democratically elected government of Ukraine and created a fascist junta, and they are the ones who would be the suspects, at least in my opinion—somebody shooting at Putin’s plane, and yet the media doesn’t even raise that as a possibility.”

Baraka immediately engages with the idea and agrees.

“And when it’s raised, it’s raised as a conspiracy,” Baraka responded. “I think that this is a—I was trying to find the citation, I remember reading, I can’t remember who it was, someone wrote about three weeks ago that we should expect false flag, a major false flag operation in eastern Ukraine that’s going to be blamed on the Russians. And that’s exactly what has happened.”

The Russian state-owned English news channel RT billed the downing of the plane a CIA false flag days after Barrett’s broadcast.

“Ajamu Baraka’s critiques of the Obama presidency have been among the most important political commentaries of the past eight years. The world would be a much better place if Ajamu Baraka rather than Barack Obama had been America’s first African-American president,” Barrett wrote in an email to The Daily Beast, calling the “witch-hunt against him due to his appearing in my book… ludicrous and libelous.”

As for MH17, Barrett said he didn’t think Baraka was certain it was a false flag. “But he is aware that there have been false flags and cointelpro-style deceptions in the past, so he sensibly is open to that possibility when suspicious events like the MH17 downing occur,” he told The Daily Beast. “And he is courageous and honest enough to discuss such matters. I wish more mainstream journalists were as knowledgeable, ethical, and open-minded.”

But Baraka’s “open-minded”-ness (he’s also referred to President Obama as “your Uncle Tom president” ) may not necessarily be the best way to draw in voters seeking an alternative to Donald Trump or Hillary Clinton. And appealing to Bernie Sanders supporters could also prove challenging, given that Baraka has said the senator from Vermont has a “commitment to Eurocentrism and normalized white supremacy.”

Then again, those statements could just be false flags.