Longtime adviser Roger Stone has said that Donald Trump “loves” the “Hillary For Prison” T-shirts sold by conspiracy theorist radio host Alex Jones and that the Republican nominee “knows exactly where they came from.” The T-shirt slogan from the 9/11 truther has now become a campaign pledge from the Republican presidential nominee.

During the October 9 presidential debate, Trump said that he would jail Democratic nominee Hillary Clinton if he is elected president. Numerous journalists have condemned the unprecedented threat as undemocratic and something you would hear in “countries with dictators.”

Mother Jones’ Tim Murphy noted Trump’s position “has been a core plank of his platform since last winter, and a fantasy of many of his supporters for far longer.” He traced the origin of the talking point to Alex Jones and his Infowars website, which began selling its “Hillary for Prison” T-shirt last year.

Jones is one of the most extreme conspiracy theorists in the country. He is the leader of the movement that claims the government was behind the 9/11 terror attacks. He has also promoted conspiracy theories about government involvement in the Oklahoma City bombing, Boston Marathon bombing, and Newtown, CT, elementary school shooting, among many others.

Roger Stone has repeatedly said that Trump has seen the Alex Jones T-shirts and “loves” them.

During a May 4 appearance on Jones’ show, Stone said that “Trump himself told me that he has seen so many of your supporters and listeners at his rallies. He loves the ‘Hillary for Prison’ T-shirts and he knows exactly where they came from. So Alex, I’m certain that he is grateful for your support.” Jones replied: “I want listeners and viewers to know, you’re having an effect.”

Stone also told author Jon Ronson that Trump praised Jones for the “Hillary for Prison” theme. From Ronson’s e-book The Elephant in the Room: A Journey into the Trump Campaign and the “Alt-Right”:

“Donald is a student of the internet,” Stone replied. “He’s an inveterate watcher, so he was well aware of who Alex is and everything Alex has accomplished. Donald told me he sees the many, many Hillary for Prison T-shirts in his crowds.”

“What does he think of them?” I asked.

“He loves them,” he said.

Stone is himself a discredited conspiracy theorist who pushes racist, sexist, and violent rhetoric. He has claimed that “Hillary must be brought to justice -- arrested, tried, and executed for murder.” Stone praised Trump’s debate call for Clinton’s jailing, stating that it was “his way of telling the Clintons and their daughter that they’re going to prison over their massive corruption.”