Donald Trump has used his Twitter account to blast his critics, pressure potential witnesses against him, and threaten to blow up North Korea. But for believers in the bizarre pro-Trump QAnon conspiracy theory, the president’s Twitter account serves a more crucial purpose, with his retweets of QAnon fans offering them badly-needed proof that their ludicrous conspiracy theory is real.

QAnon believers are convinced that Trump is secretly at war with pedophile-cannibals in the Democratic Party, a theory so unhinged and potent that the FBI considers it a potential source of domestic terrorism. Two QAnon believers have been charged with murders that appear to be motivated by their beliefs in the conspiracy theory, including the slaying of a Mafia boss, while others have committed vandalism or even shut down a bridge with an armored truck. Believers in the Pizzagate conspiracy theory, which has been incorporated into QAnon, fired shots and tried to burn down a Washington pizzeria.

Still, late last week, Trump or someone with access to his account retweeted a message of support containing the “WWG1WGA” hashtag, a reference to a QAnon motto. In total, Trump retweeted QAnon fans more than 20 times on the same day.

Trump’s Twitter activity provided new fuel for QAnon fans, who are convinced, among other things, that Trump is on the verge of arresting and executing top Democrats at Guantanamo Bay. QAnon Twitter accounts and messages boards seized on Trump’s retweets as a tacit acknowledgment of their conspiracy theory’s validity, while the retweets also provided the QAnon promoters Trump boosted with access to tens of millions of new potential believers.

“It draws more eyes,” Roy Davis—a QAnon promoter known to believers as “Captain Roy” and the co-author of an Amazon chart-topping book pushing the conspiracy theory—told The Daily Beast.

It wasn’t the first time Trump pushed QAnon on his more than 68 million followers. On Thursday, Media Matters counted more than 72 times that Trump has retweeted QAnon believers, a number that has only gone up since then.

Nor was this the first time Trump or his campaign have referred to QAnon in ways that have been seen by the conspiracy theory’s believers as proof that it’s real. In July, Trump invited QAnon promoters and other social media figures to the White House for a “social media summit.” A warm-up speaker at a Trump rally used a QAnon slogan in a speech, and Trump’s campaign featured two QAnon believers in an ad, apparently accidentally.

But QAnon believers, some of whom have alienated friends and family for their conspiracy theory, are especially desperate for validation from the president himself—or, saving that, from his Twitter account. That makes Trump’s retweets especially potent at further entrenching their beliefs.

“They certainly also get encouraged by Trump repeatedly retweeting QAnon accounts,” Travis View, a podcaster who tracks QAnon’s reach, told The Daily Beast. “They claim that Trump would never retweet pro-Q accounts if there was nothing to Q.”

It’s not clear how Trump decides which messages to retweet, and he could just be doing so without realizing the larger import of lending his endorsement to a conspiracy theory. The White House didn’t respond to a request for comment.

But not everyone in Trumpworld is so quiet. On Monday night, Trump campaign official Jessie Jane Duff ripped into QAnon believers who were celebrating rapper and actor Ice-T’s apparently accidental use of a QAnon meme in a tweet.

“I know we on the campaign don’t support Q and its all bizarre nonsense for ppl who need to believe something,” Duff tweeted. “Q is so absurd, why should the President acknowledge it when NO ONE cares? It isn’t a campaign issue. it isn’t an economic issue. It’s an issue for ppl who wish they were in the know based upon irrelevant or anonymous sources on irrelevant web sites.”

Duff soon deleted her tweets criticizing the conspiracy theory, in the face of a wave of Twitter attacks from QAnon fans.

Davis, the co-author of the QAnon book, sees Trump’s retweets as fresh affirmation that the dark global underworld imagined by QAnon fans is more than conspiracy-fodder. If QAnon was fake, in the thinking of Davis and other QAnon believers, why would the president be promoting it on Twitter?

Davis recently refinished his Corvette with a giant “Q” on the hood, using the profits from his QAnon book. Now he thinks the QAnon-related windfall from Trump could send him all the way to Washington.

“Best case is we’re up getting a medal at the White House,” Davis said.