Tucker Carlson was in particularly high dudgeon Tuesday night, his brow wrinkled in rueful anger as he launched into a public scolding on his Fox News program.

“It is probably the most shameful thing I, as someone who has done this for 20 years, has ever seen,” he proclaimed. “It’s making a lot of us ashamed to work in the same profession as those people. So reckless and wrong in the middle of a pandemic, it really is, for real.”

The source of Carlson’s apparent regret? The fact that some “members of the media” — he didn’t offer any specifics — have criticized President Trump’s energetic touting of hydroxychloroquine as a coronavirus treatment.

Sean Hannity, whose program follows Carlson’s, was mad about it, too. The drug is showing signs of success, he said, “in spite of what the mob and the media is telling you,” he insisted Monday.

Fox News’s opinionated prime-time hosts were among the earliest and most enthusiastic cheerleaders for the potential of the drug and its variant, chloroquine, to stem the coronavirus crisis — a viewpoint echoing and frequently prompting the president’s endorsement of it in his daily briefings, despite questions from the scientific community about its safety and effectiveness.

But lately their promotion has taken on a form familiar to longtime viewers — as another front in a long-running culture war against an array of supposed enemies, who are again allegedly standing in the way of what they hold to be righteous and true.

“After hearing all of the stories where hydroxychloroquine is credited with saving lives, it is amazing that the left and the medical establishment is still in total denial about the potential of these decades-old drugs,” Laura Ingraham said on her program Thursday night.

To be sure, much of the reporting and commentary on hydroxychloroquine in the mainstream media isn’t so much “reckless” as it is cautious and hedged. That’s because the scientific knowledge surrounding hydroxychloroquine is nuanced and unsettled.

The drug has been in use as an anti-malaria treatment for decades and more recently as a treatment for lupus and rheumatoid arthritis. But it’s not clear whether it works for covid-19, the disease caused by the coronavirus. Among the few preliminary studies was one showing promise, although that result was subsequently questioned by the study’s publisher. Experts have cautioned about side effects, such as heart arrhythmia, which can be fatal.

The Food and Drug Administration has given emergency approval for doctors to prescribe it to coronavirus patients from the National Medical Stockpile, but it has yet to be tested and approved through the usual process of clinical trials. Multiple trials are ongoing.

As a result, experts — such as Anthony S. Fauci and Deborah Birx, Trump’s leading infectious-diseases advisers — are at best lukewarm about the drug as a covid-19 treatment.

Appearing on Hannity’s program Monday, Birx declined to make any definitive claims about its success or venture any opinions about “the mob and the media.” Prescribing hydroxychloroquine should be “up to the physician and the patient,” she said.

This doesn’t quite reflect the ferocity of the Fox hosts’ framing of the matter, which has taken on an us-vs.-them coloration.

In touting the drug, Fox weekend host Jesse Watters denounced the “cherry-picking snakes, liars and backstabbing hypocrites” who have allegedly prevented people from receiving it. He added, “The president was hopeful but was savagely attacked in the media.”

By way of example, he played a clip of MSNBC’s Rachel Maddow calling Trump’s drug hype “cruel and harmful and needlessly diverting and wildly irresponsible from anyone in any leadership role.”

The framing of a fairly arcane medical question as a culture-war argument is part of a long pattern at Fox, where hosts often give “partisan cues” in discussing scientific questions, such as climate change, said Dan Cassino, a political science professor at Fairleigh Dickinson University who has studied the network.

“Even if there’s not a lot of disagreement in the medical community about the use of hydroxychloroquine, the fact that you can point to people on both sides means that any opinion is justified” in the eyes of Fox producers and pundits, said Cassino, the author of “Fox News and American Politics: How One Channel Shapes American Politics and Society.”

So Fox, Cassino said, will present “a scientist who says it isn’t happening and another who says it is, so there’s now a controversy. Once the debate is framed as a controversy . . . it’s no longer a question of science as to who should be believed, but a matter of opinion. That opens the door for pundits with no knowledge of the area to weigh in, as they’ve got backing for whatever they say.”

Fox’s late co-founder, Roger Ailes, often established a daily theme for the network’s opinion hosts and even its reporters, coordinating the message across the day’s programs. These thematic topics had clear and identifiable heroes and villains, whom the hosts lauded or criticized depending on the narrative established by Ailes.

While most centered on political issues — with conservatives and Republicans usually cast in the hero role or as the put-upon victims — some have touched on cultural topics.

Perhaps most famously, the network’s hosts have argued that there is a “war on Christmas,” driven by secular Democrats and retailers supposedly hostile to Christian values. Whatever its merits, the campaign was persuasive: Public-opinion polls found that over a decade, Americans’ willingness to be greeted with “Happy Holidays” instead of “Merry Christmas” dropped sharply.

The rhetoric on hydroxychloroquine follows this pattern. Hannity and his colleagues have variously emphasized that the critics of the drug are wrong, are overstating its dangers or are just out to get Trump.

The Fox hosts’ advocacy appears to be part of a feedback loop between the network and the president, reflecting Trump’s enthusiasm for the drug and prompting his repeated endorsements.

It resembles the sudden shifts in tone that Fox hosts underwent at the dawn of the coronavirus crisis — at first insisting, as did Trump, that concerns were overblown and possibly stoked by Democrats, and later pivoting, when Trump declared a national emergency March 13, to declare his efforts necessary and heroic.

Ingraham personally introduced Trump last week to two doctors who have been guests on her program and talked up the potential benefits of hydroxychloroquine.

The next day, Trump praised the drug in a televised briefing: “What do you have to lose? What do you have to lose? Take it,” he said. (He repeated the advice the following day, adding, “I’m not a doctor, but I have common sense.”)

The meeting — which was first reported by The Washington Post and which Fox has declined to confirm — would be an extraordinary breach of ethical standards at most news organizations, which typically prohibit their employees from directly advising public figures.

A Fox News representative, Carly Shanahan, declined to comment on its hosts’ comments about hydroxychloroquine. She instead pointed to more-skeptical reporting about the drug from others at Fox.

On Monday afternoon, for example, daytime host Dana Perino interviewed a former Harvard Medical School doctor, William Haseltine, who called the drug a “quack cure” with potentially dangerous side effects.

But the skeptical interviews have occurred outside prime-time hours, when the audience is far smaller than those attracted by Carlson, Ingraham and Hannity.