At Tuesday night’s presidential debate, Joe Biden hit President Trump hard on the coronavirus pandemic. Biden noted that Trump has repeatedly said the death toll “is what it is” and that he privately acknowledged the graveness of the threat in February, while continuing to play it down publicly. “The president has no plan. He hasn’t laid out anything,” the Democratic nominee said, adding: “He still doesn’t have a plan.”

A new study, though, describes one way in which Trump’s coronavirus response has been particularly consistent and impactful: in spreading misinformation.

The study from Cornell University claims to be the first to take a broad look at how misinformation has spread during the pandemic, and the one factor uniting much of it is Trump.

The study says that out of 1.1 million articles from traditional media outlets containing some kind of misinformation, 37.9 percent included a mention of Trump in the context of the misinformation. Although many of those articles also contained other subjects, included in that number are the many times in which Trump was the only subject mentioned: 10.3 percent of all articles containing misinformation.

“We conclude therefore that the President of the United States was likely the largest driver of the COVID-19 misinformation ‘infodemic,’ ” the study’s authors say. The study also has stern words for reporters, noting that they must avoid uncritically disseminating such misinformation.

The study and its methodology are likely to be extensively parsed in the days to come, and it’s possible to oversimplify the findings as “Trump is responsible for 38 percent of coronavirus misinformation,” as some already are. The media’s role in disseminating this misinformation is also worth a critical look.

For example, the study’s definitions of what constitutes misinformation are somewhat subjective and debatable. The largest misinformation category is “miracle cures,” which comprised 26.4 percent of all pieces of misinformation. Among the types of “miracle cures” included were the anti-malarial drugs chloroquine and hydroxychloroquine. Early on, reputable health officials suggested that they might indeed be beneficial, despite no scientific proof. That led the Food and Drug Administration to approve them for emergency use for a period of time, although that authorization was later rescinded in light of new evidence.

Trump clearly hyped the drugs way beyond the available data — as he has repeatedly with other treatments like disinfectants and convalescent plasma — and he publicly said he had applied pressure to gain their approval. But some of the articles the study cited as spreading misinformation covered the potential of the drug in measured ways at a time in which nothing was conclusive. One of them, for example, merely noted a surge in hydroxychloroquine prescriptions, while noting up high that a recent study had indicated that the drug might actually do more harm and that foreign medical professionals were pumping the brakes on the drug.

In the same vein, it’s worth noting that many of the mentions of this misinformation were not referencing it uncritically. The study’s authors note that just 16.4 percent of were explicit fact checks or referenced fact checks and said, “This underscores the outsized role that media professionals play in disseminating misinformation through choices made in who and what to cover.” The authors say the media often followed up with fact checks only after the misinformation had initially spread.

But much of the other coverage appears to have been skeptical without explicitly being fact-checking in nature. For example, the biggest spike in misinformation about “miracle cures” was about injecting disinfectants, which Trump floated at a news conference in late April. The coverage of Trump’s suggestion was overwhelmingly focused on ridiculing the idea and noting how dangerous it was — including in an article the study cites in its chart, via Euronews:

Medical experts have hit out at US President Donald Trump after he floated the idea of injecting disinfectant into the body to fight COVID-19.
Trump, already under fire for his coronavirus response, also appeared to suggest using ultraviolet (UV) light "inside the body".
His comments, which came on the day the US death toll from COVID-19 passed 50,000 people, sparked a backlash online.
Doctors and scientists were quick to discredit the suggestions and warned injecting disinfectant into people could be fatal.

Was this an example of Trump seeding misinformation about the coronavirus? Yes. Was it potentially dangerous? Unquestionably. But was it something that many outlets passed along uncritically? No. In fact, the reason it was the biggest “miracle cures” story was precisely because of how much it was being ridiculed.

And in fact, all four of the articles cited in the chart below included skepticism about Trump’s claims, even as they weren’t technically fact checks (though some of them didn’t convey skepticism in their headline):

Studies like this are difficult. Determining how to delineate categories is tough and subjective, as is placing articles with hundreds of words in them inside those categories. And there are very valid questions about how you cover conspiracy theories and dubious claims that may not be explicitly disproved: Do you cover them skeptically and/or fact-check them? Or do you ignore them in the name of not spreading the claims, while allowing them to spread more uncritically elsewhere?

What’s clear from this study, though, is that Trump has played a major role in pushing the media into that dilemma — as he’s done throughout his presidency on many other topics.

And if you doubt the impact of that, you need only look at how disproportionately that misinformation has taken hold in his own party. Indeed, on the final day included in the study’s data, May 26, YouGov released a poll showing 57 percent of Republicans believed a conspiracy theory that the virus was created in a Chinese lab, while 42 percent believed it was deliberately created as a bioweapon, and 44 percent believed Bill Gates wanted to use a mass vaccination program to implant microchips in people. Fewer than a quarter of Democrats agreed on each of these points.