The president spins falsehoods solely to make us afraid — of immigrants, of the left, of one another.

It took Donald Trump to make me associate Franklin Roosevelt with Pennywise the Dancing Clown.

It was Roosevelt, of course, who, in his first inaugural address, said that “the only thing we have to fear is fear itself.” That remarkable speech, delivered before Congress on March 4, 1933, is worth revisiting, and not least for the dignity of its rhetoric. The speech outlined the strategy with which Roosevelt would combat the Great Depression; its hope was to inspire, to bring people together and above all, to reassure the nation that we would “revive and prosper.”

The primary obstacle to this restoration was not economics but fear: “nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance.” A key strategy for conquering that fear, he went on, is speaking with candor: “This is pre-eminently the time to speak the truth, the whole truth, frankly and boldly.”

If, 85 years later, you wanted to imagine the presidency of Mr. Trump in a nutshell, simply take all of the generousness and wisdom in Roosevelt’s first inaugural address and do the opposite.

The only thing Mr. Trump has is fear itself.

He wants us to be afraid, for it is fear that divides us, that sets us one against the other. If there is anything frank and bold about this presidency, it is Mr. Trump’s ability to invent falsehoods out of fairy dust and marzipan, solely to make us afraid — of immigrants, of transgender people, of one another.

It doesn’t matter to him that most of the things he urges us to be afraid of pose no danger. What matters is that his paranoid inventions suck up our attention and make us focus, week after week, upon him.

Those of us in the media devote endless hours to refuting the latest barrage of hooey emanating from the White House. But even in this, we’re still amplifying his noise and nurturing, even in the process of refutation, the fear on which the man thrives.

All of which makes covering this White House very difficult indeed. When Jim Acosta’s press credentials were suspended recently, the British journalist Jane Merrick suggested a mass boycott of the briefings. But as Masha Gessen in The New Yorker observed, this action “would mean walking away from politics altogether, which, for journalists, would be an abdication of responsibility.”

So we can’t ignore him, and we can’t report on him without engaging in his game. In so many ways we’re trapped — which is, one suspects, exactly what this president wants.

There’s a well-worn trope in horror fiction about the Monster Who Feeds on Fear. These are creatures or forces who thrive on negative emotions and whose power over you is in direct proportion to the terror they can generate: Vincent Price’s “The Tingler”; the Scarecrow character in the Batman franchise; Marvel Comics’ Mister Fear; the Dark Side in “Star Wars.”

The most fully imagined of these monsters, in my opinion, is Stephen King’s Pennywise the Dancing Clown in the novel “IT,” who prefers above all to devour children, because their fears are the easiest to manipulate. It’s a process he compares to “salting the meat.”

If this were a horror movie, our heroes would understand that the only way to defeat the monster is by refusing to be afraid of it, to shrink it through indifference.

This being reality, though, that path is really not available to us — either as journalists or as citizens. Try as we might, we cannot ignore the president of the United States.

But we still have options.

One of them is legal action. PEN America — the advocacy group promoting free expression worldwide (and on whose board I serve) — filed suit this fall in federal court to stop President Trump from using the machinery of government to retaliate or threaten reprisals against journalists and media outlets for coverage he dislikes. There is other legal action pending against Mr. Trump and his administration as well, including whatever emerges from the Mueller investigation.

These actions will give this president ample reason to feel some of the fear he has inflicted on others.

The other strategy is the one thing that Mr. Trump appears to fear most, for it is the one thing that all his riches and power have apparently never brought him. And that thing is a sense of humor.

In J.K. Rowling’s “Harry Potter” stories, one of the most terrible creatures our young heroes can face is the boggart — a creature that feeds on fear. A boggart takes the form of whatever it is you fear the most. Harry sees a wraithlike creature called a Dementor; Ron Weasley sees a giant spider; Neville Longbottom sees the cruel and mysterious Professor Snape.

These apparitions are not dispelled through violence, or cruelty, or by building a giant wall. In the genius of Ms. Rowling’s imagination, they are vanquished with a charm called “Riddikulus,” which turns the boggart into an object of derision. In the wake of this charm, Ron’s spider winds up on roller skates; Neville’s Snape finds itself in his grandmother’s pajamas.

It’s no coincidence that this president is famous for having no sense of humor. It is comedy, above all, that peels the masks off liars and reveals the truth — the virtue that Roosevelt deemed most necessary to convert retreat into advance.

Want to conquer fear? Tell better jokes — and not the easy kind, salted with cruelty and malice, but the more complex, generous and fundamentally American variety, as pioneered by Mark Twain, or Richard Pryor, or Lily Tomlin.

Let the rule of law, the power of truth and the subversion of humor vanquish this boggart for good. In so doing we shall assert our firm belief: The only thing we have to fear is Trump himself.