On Monday, Jon Stewart, the comedian who as host of “The Daily Show” became a critic of the Iraq war, embraced the false claim that COVID-19 was created by Chinese scientists.

Stewart was the featured guest on “The Late Show” with Stephen Colbert, his former colleague at “The Daily Show,” on the first day that Colbert’s show returned to the air with a live studio audience.

For over a decade, Colbert and Stewart have had a recurring gag pretending to be deranged right-wingers. Over the years, as the two moved further and further to the right, pieces of the schtick would chip away, leaving the disturbing reality that they were becoming the people they parodied.

On Monday, nothing was left of the gag: Only the shocking reality that a man who had been a vocal opponent of the Bush administration’s lies and war crimes was raving like a fascist lunatic on live television.

Stewart screamed that scientists were going to “kill us all,” shouting obscenities as he condemned “logic” and promoted a fascist conspiracy theory.

The COVID-19 pandemic, Stewart said at the beginning of the interview, was “caused by science.” Colbert, playing the “straight guy,” pretended to be taken aback.

“Do you mean perhaps there’s a chance that this was created in a lab?” Colbert asked. “A chance?” Stewart deadpanned. “There’s a novel respiratory coronavirus overtaking Wuhan, China, what do we do? Oh, you know, who we could ask? The Wuhan novel respiratory coronavirus lab. The disease is the same name as the lab.”

From there, Stewart’s eyes began to glint. He got up, and began screaming, pounding Colbert’s desk, pointing his finger at the audience. “LOOK AT THE NAME!” Stewart yelled.

He went on to make the same argument, over and over, screaming the whole time. If there were an outbreak of “chocolaty goodness” near Hershey, Pennsylvania, “IT’S THE F*CKING CHOCOLATE FACTORY,” Stewart continued screaming.

The pandemic was a “BIG F*CK-UP,” Stewart yelled.

Stewart’s argument, to the extent that his rant could be called one, was summed up by his retort to Colbert when the latter asked for a more serious explanation. “Stop with the people and logic and things.”

It was the type of absurd, irrational, antiscientific non sequitur that Stewart and Colbert built their careers ridiculing.

Colbert will be remembered for his 2006 monologue at the White House Correspondents’ Association dinner, in which he excoriated George Bush’s antiscientific irrationalism, declaring, sarcastically, “Guys like us, we don’t pay attention to the polls. We know that polls are just a collection of statistics that reflect what people are thinking in ‘reality.’ And reality has a well-known liberal bias.”

In the early 2000s, broad sections of the population were disgusted with the Bush administration: its lies about Iraqi weapons of mass destruction, its war crimes, its attacks on democratic rights, its promotion of religious bigotry and connections to the extreme right.

Stewart and Colbert tapped into these sentiments. Their “fake” news show became one of the only outlets on cable television in which the motives of the Bush administration and its “war on terror” could be questioned.

As one academic commented, “When all the news guys were walking on eggshells, Jon was hammering those questions about WMDs… That’s the kind of thing CNN and CBS should have been doing.”

The Guardian summed up Stewart’s influence as follows: “He was an essential opponent of the Iraq war and a searing critic of the Bush administration. He was an equally acute—and feared—expounder on the flaws of the mainstream media.”

And now Stewart has been reduced to screaming his head off on late-night television, advocating a hoax invented by the fascist Steve Bannon and promoted by Michael R. Gordon, the coauthor with Judith Miller of the debunked New York Times article claiming Iraq was seeking “aluminum tubes” to create nuclear weapons.

Notably, Stewart played a role in publicly debunking the Bush administration’s lies about Iraq’s weapons of mass destruction. When, well past his prime, Stewart interviewed Miller in 2015, he accused the discredited journalist of publishing what US intelligence agencies “were feeding you.” Now, it is Stewart who is regurgitating what he has been “fed.”

If Stewart were the only former opponent of the Iraq war advocating the “Wuhan Lab” conspiracy theory, the 21st century version of “weapons of mass destruction,” it could be explained away as a tragic story of a misguided individual.

But Stewart joins a growing number of former critics of US imperialist policy who have embraced the Wuhan lab lie. Blazing the trail was Bill Maher, the former Iraq war critic and supporter of Barack Obama, who promoted the conspiracy theory in January of this year.

He was joined by Glenn Greenwald, the former collaborator of whistleblower Edward Snowden and former critic of US imperialism, who has since become an open apologist for former president Donald Trump and his fascist movement. Greenwald complained in May of “media/liberal resistance… to the possibility of a COVID lab leak.”

Jacobin writer Branko Marcetic recently demanded that this conspiracy theory be treated as legitimate. “The dismissal of calls to take the lab-leak theory seriously on the basis that it’s a US govt conspiracy to undermine China doesn’t make much sense,” Marcetic wrote. “Also not convinced the theory being true would be like the Iraqi WMDs.”

Stewart, Maher, and Greenwald express a broader social trend. Critical of certain aspects of imperialist policy, their outrage over the Iraq war was never rooted in an orientation to the working class and the struggle against the capitalist system. Their outlook was, fundamentally, one of middle-class rage.

Marxists have long pointed to the phenomenon of the “enraged petty bourgeois,” who can in certain historical periods swing violently and sharply to the right.

Now Stewart, Maher, and Greenwald and the social layer they speak for have been swept up by powerful right-wing currents in contemporary politics, unmoored by a vast social crisis all around them, which they do not understand and for which they are politically unprepared.