On Sunday, February 16, as COVID-19 was tightening its stranglehold on China and plotting a cruel blitz against the United States, Republican Senator Tom Cotton went on Fox News and floated an alternative theory about the provenance of the deadly disease. The early scientific consensus was that the never-before-seen coronavirus had most likely made a jump from bats to another form of wildlife, perhaps the type of exotic animal, like a pangolin, sold at Wuhan’s Huanan Seafood Wholesale Market, where it then achieved a natural zoonotic transmission to humans. Cotton wanted Fox News Channel’s viewers to hear about another possible origin story. The seafood market, he noted, was not that far from a major biosafety lab.

“We don’t know where it originated, but we do know that we have to get to the bottom of that,” Cotton told Maria Bartiromo. “We also know that just a few miles away from that food market is China’s only biosafety level 4 super laboratory that researches human infectious diseases. Now, we don’t have evidence that this disease originated there, but because of China’s duplicity and dishonesty from the beginning, we need to at least ask the question to see what the evidence says. And China right now is not giving any evidence on that question at all.”

Cotton didn’t say so outright, but there was an unmistakable subtext to his commentary, implying that SARS-CoV-2 could even have been man-made. “We have such laboratories ourselves in the United States run by our military,” he continued, “in large part done for preventative purposes, or trying to discover vaccines or protect our own soldiers. China’s obviously very secretive about what happens at the Wuhan laboratory.”

The theory added a scary new layer to Donald Trump’s blame-China strategy, and Cotton didn’t pull it out of thin air. The theory had been circulating for weeks, mostly in conservative media and shadowy Facebook reposts. But now the Arkansas senator had amplified it on a massively influential national media platform, and the journalistic establishment took notice. “Tom Cotton keeps repeating a coronavirus conspiracy theory that was already debunked,” said a Washington Post headline, while the New York Times similarly declared, “Senator Tom Cotton Repeats Fringe Theory of Coronavirus Origins.” Experts came forth with buckets of cold water for Cotton’s remarks. “It’s a skip in logic to say it’s a bioweapon that the Chinese developed and intentionally deployed, or even unintentionally deployed,” one told the Post, adding that exposure by way of a lab accident was also “highly unlikely.” A health expert with outbreak experience acknowledged to Jake Tapper that “the rumor is circulating but there is no evidence to date that this is true. Hopefully the [World Health Organization] team will get the samples from the original cases and we will be able to figure this out. Until then, I put it in the conspiracy theory bucket… I wouldn’t mention it without any more data to rely on.” Tapper’s expert did, however, add a caveat: “It is quite possible. Just don’t know how probable. And if wrong, what does the accusation do to collaboration“ with China? (Cotton, for his part, went on Twitter to clarify that he did in fact think a natural outbreak was the most likely scenario, and that if the virus had originated in a lab, he believed it would have been the result of an “accidental breach.”)

Over the past week or so, just a couple of months after it had been knocked down and sent packing back to the fringe, the lab-leak scenario has begun to rear its head once again, this time entertained by credible journalists. On April 2, the Washington Post’s David Ignatius published a column titled, “How did COVID-19 begin? Its initial origin story is shaky.” That piece, which made a case for the plausibility of a lab accident, was followed two days later by a story from Glen Owen, political editor of Britain’s Mail on Sunday: “Did coronavirus leak from a research lab in Wuhan? Startling new theory is ‘no longer being discounted.’”