The conference held in Washington, D.C., last Saturday by the National Policy Institute should have dispelled any lingering illusions about the “alt-right.” In the final speech of the night, Richard Spencer, the movement’s de factor leader, referred to the press as “soulless golem” and, with a conspiratorial grin, recommended referring to them “in the original German” as the lügenpresse (lying press), a phrase popularized by the Nazis in the 1920s and 1930s. In a further echo of the European far right, Spencer shouted out, “Hail Trump, hail our people, hail victory!” which members of the crowd answered with arms upraised in the familiar Nazi manner.

But Spencer doesn’t think that these Nazi salutes are the smoking gun proving that his white-nationalist movement is fascist. He texted PBS Newshour producer P.J. Tobia that they were “clearly done in a spirit of irony and exuberance.” On the program NewsOne Now, Spencer said the Nazi salute was done “in fun.”

Spencer’s defense of his followers making a Nazi gesture as being little more than a joke is a familiar protective gesture. Anyone who has dealt with online far-right trolls—the kinds of people who love to photoshop images of contemporary people being sent to concentration camps, along with more clearly jocular cartoons featuring Pepe the Frog—will be familiar with the way grisly, would-be humor is intermixed with bigotry. The intent seems to be to create a kind of plausible deniability, so if the racism is challenged, there is a prepared rejoinder: Can’t you take a joke?

But the pretext of irony as a way of furthering bigotry isn’t just a tactic wannabe Nazis of the 21st century have developed. It’s actually indistinguishable from how the actual Nazis of the early 20th century behaved. This role irony plays in providing a protective cover for anti-Semitism was brilliantly analyzed by the philosopher Jean-Paul Sartre in his book Anti-Semite and Jew (1944), published after France was liberated but while the Holocaust was reaching a crescendo in Europe. Sartre observed that anti-Semites often resorted to the cloak of jokiness:

Never believe that anti-Semites are completely unaware of the absurdity of their replies. They know that their remarks are frivolous, open to challenge. But they are amusing themselves, for it is their adversary who is obliged to use words responsibly, since he believes in words. The anti-Semites have the right to play.

They even like to play with discourse for, by giving ridiculous reasons, they discredit the seriousness of their interlocutors. They delight in acting in bad faith, since they seek not to persuade by sound argument but to intimidate and disconcert. If you press them too closely, they will abruptly fall silent, loftily indicating by some phrase that the time for argument is past.

A good example of what Sartre had in mind was the novelist Louis-Ferdinand Céline, a brilliant writer who besmirched himself by descending into Nazi apologia with his 1938 tract, Trifles for a Massacre (Bagatelles pour un massacre).

As scholar Patrick McCarthy noted in his 1977 critical study, Céline “exaggerates to the point of creating disbelief” in Bagatelles. In that pamphlet he sees Jews everywhere, saying that the Pope is Jewish (real name “Isaac Ratisch”) and the entire nation of England is Jewish. The novelist blames Jews for everything from the treaty of Verdun in 843 CE to downfall of Napoleon to the popularity of surrealism.

It’s possible to dismiss Céline’s hateful rant as being nothing more than a big, bad joke. Andre Gide, for one (who Céline had falsely described as Jewish) took it as a satire since he couldn’t believe an intelligent person would mean such things literally. But it’s impossible to dismiss Céline’s anti-Semitism as a mere joke when we consider his active propaganda during the German occupation of France, where he egged on violence against Jews.

But Sartre’s analysis helps us understand that it’s precisely the line between literalness and fabulation that anti-Semitism tries to erase. Fascism is a kind of fantasy politics, a nihilistic leap into pure willfulness, beyond the claims of facts and logic. For the bigot, jokes are a foot in the door to help slip that element of fantasy into ordinary discourse. If we accept the excuse that “it’s just a joke,” we’re allowing comedy to help create the complicity that normalizes bigotry. Soon after, jokes stop being jokes, as they did in occupied France in the 1940s, and Céline’s rhetorical violence suddenly became the pretext for real killings.