There’s a scene in the movie “Oppenheimer” in which Ernest Lawrence, the inventor of the cyclotron and head of his own lab at UC Berkeley, reacts angrily when he discovers his friend J. Robert Oppenheimer trying to recruit lab assistants to a communist-linked campus labor union.

It’s one of the few scenes in this largely factual film that may actually have downplayed the real event. Lawrence was beyond furious at Oppenheimer for bringing politics — and left-wing politics at that — into the lab. For Lawrence — whose personal journey would transform him from New Deal liberalism to solid Republican conservatism — a scientific lab was no place for anything but pure science, uninfected by politics.

It’s one of the tragedies of Lawrence’s life and career that he ultimately was unable to keep his lab politics-free. He would be swept up in UC’s capitulation to the 1950s red scare in California, which culminated in the mandate that all faculty sign an anti-communist loyalty oath.

In acceding to the mandate by requiring his lab staff to sign the oath in order to assuage the right-wingers on the UC Board of Regents, Lawrence — the most famous and eminent scientist on the Berkeley faculty — discovered that in a turbocharged partisan atmosphere, no science laboratory could keep politics from crashing through the door.

Scientists in today’s America are relearning that lesson. Two who learned it the hard way are Peter Hotez, an eminent vaccinologist affiliated with Baylor College of Medicine, and Michael E. Mann, a climatologist and geophysicist at the University of Pennsylvania. They’ve collaborated on a new book, “Science Under Siege,” that analyzes the forces fueling the politicization of science and its consequences and map out a possible path out of the wilderness.

Both come to the topic via personal experience. After Hotez’s frequent television appearances speaking out against misinformation and disinformation about vaccines, he and his family came under attack.

“This translated into death threats and in-person confrontations at his lectures and even at his home,” they write.

Mann was publicly vilified over his research showing that average global temperatures had risen sharply since 1900 after about a millennium of gradual cooling, producing what became known as the “hockey stick graph.”

The attacks on Mann encompassed death threats and “demands for him to be fired from his job, all because his findings threaten the profits of the fossil fuel industry.”

The scientists write of being “attacked online through email and social media…. Fox News and other conservative news media outlets portray us as cartoon villains or public enemies. Extremist members of the US Senate and House denounce us for their political gain.” The “high-profile attacks … serve as dog whistles for a pile-on.”

Small wonder that scientists are reluctant to take a public stand against anti-science claptrap — apart from the risk that by fighting back against partisan interference, scientists could fall into what the Atlantic’s Katherine J. Wu identifies as a Catch-22: running the risk of “advancing the narrative they want to fight — that science in the U.S. is a political endeavor.”

That narrative is true up to a point: Federal funding for science through institutions such as the National Institutes of Health, National Science Foundation and NASA, as well other executive branch agencies, is under congressional control, which makes it fundamentally political.

But for most of the history of those agencies, political hadn’t meant partisan. The NIH, NSF and NASA generally have had bipartisan support, in part because they were seen as advertisements for America’s wealth and intellectual potency.

There have always been naysayers, of course — lawmakers who brought snowballs into the Senate chamber to dispute global warming, or who took legislative testimony fantasizing the COVID vaccine made people magnetic. But for the most part they were regarded as fringe characters. It’s also proper to note that the root of much science denial is economic — global warming skepticism advantages the fossil fuel industry, and doubts about the links between smoking and cancer were promoted by tobacco companies.

But American scientists haven’t seen attacks on their work as concentrated and direct as what they’re seeing now.

The Trump administration has terminated billions of dollars in research grants simply because they’re related to diversity or gender study, fired scientists from advisory panels based on unwarranted accusations of conflicts of interest, and ended research on COVID vaccines based on flimsy assertions that they’re unsafe. They’ve issued official reports containing misrepresented or fabricated studies.

One needs a scorecard to track the devastation wreaked on scientific efforts by the current administration. As it happens, one exists: the Silencing Science Tracker posted by Columbia Law School. It makes dismal reading. In July alone, the Environmental Protection Agency announced it would close its office of research and development, cashiering 3,700 workers; the Department of Agriculture said it would close most of its forest research stations nationwide; and NASA removed the congressionally mandated national climate assessments from its website.

Elon Musk’s DOGE service has claimed to have saved the federal government as much as $44 billion through more than 15,000 grant terminations, many of the grants originally issued by NSF, NIH, or other units of the Department of Health and Human Services.

According to the “Bethesda Declaration,” an open letter to NIH Director Jay Bhattacharya published in June and signed by nearly 500 NIH employees criticizing the administration’s prioritization of “political momentum over human safety and faithful stewardship of public resources,” the NIH had terminated 2,100 research grants totaling $9.5 billion since Trump’s inauguration.

But those terminations “throw away years of hard work and millions of dollars,” the declaration observed: “Ending a $5 million research study when it is 80% complete does not save $1 million, it wastes $4 million.”

The terminations also “shirk commitments to participants, who braved personal risk to give the incredible gift of biological samples, understanding that their generosity would fuel scientific discovery and improve health”; “risk participant health” by abruptly stopping medications or leaving participants with unmonitored device implants; and “damage hard-earned public trust.”

Hotez and Mann identify five anti-science forces driving the politicization of science: plutocrats preserving their fortunes, petrostates preserving their export revenues, professionals using their scholarly credentials “to deceive or promote unsupported contrarian views,” propagandists skilled at using social media to amplify their claims and press outlets portraying information and disinformation merely as two sides of an unresolved debate, even when the facts pile up on one side.

How can the anti-science movement be defeated? Hotez speaks frequently in public and has written two previous books refuting anti-science sophistry. Mann won a jury verdict last year against conservative writers he sued for defamation, although the judge in the case reduced the jury’s $1-million punitive damage judgment to $5,000 — and the judge subsequently imposed a charge of nearly a half-million dollars in legal fees against him. Mann told me he’s confident that the ruling will be overruled on appeal.

“The good news is that there is still time to oppose the antiscience siege,” Hotez and Mann write. “The antiscience disinformation enterprise has expanded, professionalized, and organized into a vast and well-financed entity that exerts influence at the highest levels of the U.S. government; it spreads disinformation and propaganda through the news media, podcasts, books, websites, and antisocial media.”

The obstacles are legion, however. Young scientists are naturally reluctant to expose themselves to anti-science obloquy; the straitened condition of the national press has led to mass layoffs of journalists with the knowledge and skill to communicate scientific truths.

Hotez and Mann write that scientists must take to the battlefield. They advocate educating young scientists in how to communicate to the public about how they work, presenting an “easily recognizable public face so we are not seen as white-coated oddballs lurking in dark corners.”

That means “a dramatic shift in the incentive structure” in science to “properly reward scientists who spend substantial time and effort on public outreach.”

The stakes are so great that the challenge can’t be overlooked, they write. America’s “scientific infrastructure is beginning to crumble. Because America is a nation built on science, this assault threatens our place in the world. And without American leadership, there is little hope for addressing the global crises we face.”

They conclude: “We must take back our politics. We need to restore the rightful role of science in our political and societal discourse.” Given the twin menaces of global warming and pandemic threats, “the reality, now, is that human civilization is in actual grave danger.”