At 10:40 on Sunday night, a longtime adviser to Donald Trump tweeted that Khizr Khan—the Gold Star father who’s emerged as one of the candidate’s most effective critics—was an “agent” of an Islamist cabal. It’s an opinion, less than a day later, that’s become an article of faith to many in Trumpworld.

It’s also the product of the fevered imagination of Theodore “Shoebat,” the pseudonymous conspiracy theorist and Islamophobe who has made a career of spreading nonsense. That is, when he’s not calling himself a “proud fascist.” His dad and fellow conspiracy-monger, Walid, isn’t much better. He swears that Zika is a punishment from God, and likens homosexuality to cannibalism.

Trump and his team have long leaned heavily on conspiracy theorists and online bullshit artists for many of their most memorable moments. Trump suggested that Ted Cruz’s father was part of the plot to kill JFK. (Wrong.) He claimed that large numbers of American Muslims openly cheered fall of the Twin Towers, when no evidence for such celebrations exist. And then there’s the whole birther thing.

But suggesting that the father of a fallen U.S. soldier is secretly an enemy of America—that’s new. Thank Walid and Ted Shoebat for that.

Walid Shoebat’s biography reads like a cautionary tale. Born in Bethlehem to an American mother and Palestinian father, he claims to have been a radical Muslim, a member of PLO, and a prisoner in Jerusalem. Then, Shoebat says, he was recruited for radical jihad. It’s a story that even the most ardent Muslim-haters say is untrue.

Shoebat says he accepted Christ as his Lord and savior in 1994. Today, he peddles this biography to rally concern about Islam and paranoia about jihadists hiding in every mosque—and every college.

“The U.S. university campuses are a major recruiting ground for terrorists,” he claimed.

It’s all the more telling, then, that he attacked Khizr Khan, the father of an Iraq War hero, as an “agent” of the Muslim Brotherhood, which he believes to be “the cartel and mother umbrella of all terror organizations.”

The deeply incriminating information about Khizr Khan apparently stems from an academic article he wrote about Islamic Law. Because Khan cited a Muslim Brotherhood leader as an important source for his article, the Shoebats accused him of being the organization’s acolyte in a blog post published on Sunday.

“Khan wrote [the paper] in the eighties while he was in Saudi Arabia, the motherland of Wahhabism. This would never be possible unless Khan clearly had the support of the Saudi Wahhabist religious institution,” the Shoebats concluded.

In Egypt, the Brotherhood’s birthplace, however, it often competes with Wahhabist parties in elections.

Khan runs a law office that provides immigration services. Thus, “Most likely Khan was working to bring Muslims into the county,” the Shoebats conclude.

They fail to mention that Khan, the proud father of a servicemember who died a hero, boasts proudly about providing pro bono legal services for U.S. military families, right there on his homepage.

But the Shoebats don’t follow Trump’s lead of only casting doubt on the deceased hero’s parents. They impugn the character of the fallen soldier, Capt. Humayun Khan, himself. They compare him to the likes of Nidal Malik Hassan, the Muslim-American soldier who carried out the massacre at Fort Hood.

“Is it likely that Khan’s son was killed before his Islamist mission was accomplished? Only another type of investigation will determine that,” they wrote. “Do they ever mention how many soldiers have died because of Muslim traitors? Do they ever bring up how many Christians in the US military were killed? Yet the modernists and homosexuals continue to attack Christians.”

But not even calling an American hero a terrorist stopped Trump’s advisers from pushing the unsavory story. Shoebat’s willful lies about Khan’s beliefs and history were picked up and tweeted as gospel by Trump’s veterans affairs adviser, Al Baldasaro. Baldasaro pushed out the article comparing Humayun Khan to a terrorist to his Twitter followers.

“Read the truth about your hero, Mr Khan who used his son as Political Pawn,” he wrote.

Trump confidant Roger Stone, who no longer serves the campaign in an official advisory role but is nonetheless close to the nominee, also tweeted the inflammatory article.

“Mr. Khan more than an aggrieved father of a Muslim son—he’s Muslim Brotherhood agent helping Hillary,” Stone tweeted with a link to the fabulist narrative.

Perhaps the Trumpkins approving tweets should come as no surprise. After all, the Shoebats and Team Trump have a common enemy: Hillary Clinton.

Shoebat’s son Ted, best known for his homophobic screeds, is also behind such masterpieces as “Read About the Horrific Ways Hillary Clinton Will Have Children Murdered if She Becomes President.”

“Hillary (or should I say, ‘Hitlery’),” the post begins.

“This woman is absolutely evil, a modern day Jezebel,” Ted rages, before copying and pasting from The Christian Post. “The American people cannot vote in this female Hitler!”

(And he also claims that gays are an inherently violent group that thirsts to kill Christians. In one tweet, he even identified himself as a “proud fascist.”)

A whole section of Shoebat.com is dedicated to slandering top Clinton aide, Huma Abedin. She also has deep ties to the Muslim Brotherhood, according to the Shoebats.

And, just like Donald Trump, Shoebat suggested that the Khizr Khan’s speech was carefully crafted by a Clinton operative. In fact, Khan spoke extemporaneously about his son and his frustration with Trump’s proposed policies.

In May, the elder Shoebat announced that he quit air travel two years ago for fear of his planes being taken down by Muslim pilots.

And he believes the Zika virus, which has been linked to encephalopathy in newborns, is God’s punishment for sin, likening its spread to HIV. Both, he suggests, are punishments for a sinful sexual nature.

“God says throughout the Bible that He can only put up with so much. When God gets angry at times He sends His private armies,” Shoebat wrote. “In Joel 1-2 it was locusts and in Isaiah 18:1-6 it was mosquitos. Read the verses.”

And while he’s less focused on the gay agenda than his son, Walid told radio host Joe Miller in March 2015 that Islamic tyranny is just the start of a slippery slope to cannibalism and homosexuality. After Omar Mateen pledged allegiance to ISIS and slaughtered 50 Americans at a gay club in Orlando, Walid Shoebat said that the “only ones moaning over fifty gays slaughtered are liberals, idiots and gay lovers.”

A CNN expose on the elder Shoebat in 2011 found that he rakes in a hefty salary from lecturing and book sales, but that details to back up his self-reported biography are few and far between.

(A 2014 tax return obtained by The Daily Beast for the Forum for Middle East Understanding, Shoebat’s nonprofit, said it brought in a gross income of more than $1.7 million. Shoebat was paid $87,995, it said.)

“CNN reporters in the United States, Israel and the Palestinian territories found no evidence that would support that biography,” the report read.

(Even Debbie Schlussel—another far-right critic of Islam, who targets many of the same groups as Shoebat—called him a “fake terrorist” and dismissed him as unhinged.)

The CNN reporters found no relatives to confirm his story, and no evidence of a firebombing he had allegedly participated in, nor records from a Jerusalem prison verifying his incarceration. They found inaccuracies in the information he presented at a conference, and sometimes whole organizations have denied publishing research Shoebat attributed to them.

Shoebat responded to the CNN profile on his website, accusing the network of collaborating with the Council on American-Islamic Relations, an advocacy group Shoebat is critical of, “in carrying out this political assassination of Mr. Shoebat.” But he’s never publicly produced proof of any of the improbable claims in his life story.

Shoebat did not respond to a Daily Beast request for comment.