Washington • I had supposed President Trump was causing only his opponents to freak out, not his supporters. Then I heard Wayne LaPierre.

To see the National Rifle Association boss speak this week at the annual Conservative Political Action Conference was to see a man in urgent need of mental-health intervention. He turned a conventional speech about guns (specifically, the need for more of them in schools) into a paranoid fantasy about a socialist takeover of the United States.

He saw a “tidal wave” of “European-style socialists bearing down upon us,” creating a “captive society,” eliminating “resistance,” making a “list” in a cloud database of those who spank their children, expunging the “fundamental concept of moral behavior,” controlling speech through “safe zones.”

With this “new socialist wave in America,” he said, “it’s just a short hop to the systematic destruction of our most basic freedoms.”

Had LaPierre fallen on his head and awakened in 1964? All that was missing was for him to quote General Jack D. Ripper in “Dr. Strangelove” on “the international communist conspiracy to sap and impurify all of our precious bodily fluids.”

And just who is perpetrating this red invasion, 27 years after the Soviet Union fell? Our billionaire president, who with his Cabinet and staff of billionaires and Goldman Sachs executives just secured a $1.5 trillion tax cut for the rich? The Republican-controlled Congress, which seeks to dismantle the social-safety net and business regulations? The pro-business majority on the Supreme Court?

LaPierre singled out three billionaire capitalists to blame for the socialist revolution: George Soros, Michael Bloomberg and Tom Steyer. But he saw conspirators everywhere in the government -- Trump’s government: the FBI (with its “corruption” and “rogue leadership”), the Justice Department, the Environmental Protection Agency, the intelligence agencies. He also blamed the Democrats, media, Hollywood, universities, classrooms, Black Lives Matter, elites and Keith Ellison.

Even the CPAC audience seemed to be stunned by this unhinged time-traveler from the Cold War. “You know, I hear a lot of quiet in this room, and I sense your anxiety,” he said. “And you should be anxious, and you should be frightened.”

LaPierre was so frightened and anxious that CPAC wouldn’t list a time for his speech in advance, to avoid protests. He travels with a huge security entourage, even though his opponents eschew guns. Does he think he will be pelted with sprouted quinoa?

And it isn’t just LaPierre. His group’s spokeswoman, Dana Loesch, exhorted the CPAC crowd to turn against reporters in the room, saying “many in the legacy media love mass shootings” because “crying white mothers are ratings gold.”

I am empathetic. None of us are at our best these days. We are on edge -- even those who like Trump. We can’t help it; it’s in our brain chemistry.

A new book by neuropsychologist William Stixrud and my friend Ned Johnson provides an explanation. The book, “The Self-Driven Child,” explains how calm parents give their kids more sense of control and help them perform better.

The science is simple. If you are calm, your executive functions handled by the brain’s prefrontal cortex — organizing, problem-solving, self-control, decision-making — perform well. If you are overly stressed, those functions decline as your brain floods with cortisol. Stress is contagious, and if you are in the presence of somebody who is out of control — a parent, an employer or, say, a president — your own executive functions decline.

“It’s a terrible thing for a chief executive of anything to be fear-mongering or emotionally reactive,” Johnson explains, “because all the bright capable people around you become less bright and less capable if they’re overly stressed.”

You don’t have to be the focus of the person’s ire or in the person’s physical presence for the stress to spread. A 2014 study in the Proceedings of the National Academy of Sciences found that those who watched six hours or more of media about the Boston Marathon bombings reported higher stress than those present at the bombings. And Trump is almost a perfect stress-inducing machine, hitting all the buttons that University of Montreal psychiatry professor Sonia Lupien lists as causes of stress: novelty, unpredictability, perceived threat to safety or ego, and a low sense of control.

In theory, some who support Trump would be less affected, because they might feel comforted by an I-alone-can-fix-it authority figure. But, as poor Wayne LaPierre shows, no one is immune.

Being led by a man who rages out of control makes all of us — friend and foe alike — more like that ourselves.

Dana Milbank

Follow Dana Milbank on Twitter, @Milbank.