Just days before Christmas, Thibaut Chevillard, a journalist with the French newspaper 20 Minutes, observed a harrowing scene on the Paris metro. A group of drunken gilets jaunes—“yellow vests”—on their way back from protests that have gripped France for the past two months, entered the train and began making the quenelle with their arms. A sort of inverse Nazi salute—one arm pointed towards the ground at an angle while the other hand crosses the chest and touches the shoulder—the gesture was popularized by the notoriously anti-Semitic French comedian Dieudonné over a decade ago. Dieudonné, who now sells neon yellow traffic vests on his website, originally accompanied the salute with a vulgar rewording of the “Chant des Partisans,” a melody from the French Resistance.

Chevillard watched as a 74-year-old woman approached the three men, identified herself as the daughter of an Auschwitz victim, and asked them to stop. They laughed. One claimed that gas chambers never existed. Then they began chanting, “Throw this woman out!” The woman went back to her seat. Nobody stood up for her for fear of a physical altercation, Chevillard later tweeted with guilt, including himself. She got off in silence at the next stop.

Earlier that afternoon, Yahoo News had tweeted a video of a separate group of yellow vests in Montmartre singing la quenelle and making the gesture with their arms. Both sets of gilets jaunes would have been aware of the meaning of the song and the salute. As the French newspaper Le Nouvel Observateur wrote, the quenelle “is a coded anti-Semitic hymn, and those who sang it could not be ignorant of that, unless they have spent the past few years on another planet.”

The incidents provoked an immediate backlash from the French political class, and a spate of soul-searching articles in left-wing media about what the yellow vests were becoming. They could have saved their shock, because despite the legitimate economic pain and despair that have been highlighted by the protests, anti-Semitism, conspiracy theories, illiberal politics, and violent insurrectionism have been inextricable from the movement practically from its beginning.

As far back as November 19, there were reports detailing incidents of racism, homophobia, and Islamophobia at the blocked traffic circles where the yellow vests made their stand. But above all, it is the anti-Semitism that has been remarkably constant. In early December, Hervé Lalin, a noted far-right militant anti-Semite, inadvertently made the cover of Paris Match, when he was photographed facing off against a police officer (the magazine later said that nobody on staff had recognized him when it selected the photo). Posters and graffiti declared that French President Emmanuel Macron is “the Jews’ bitch” and “Jewish trash,” that “Macron = Zion,” and that he is guilty of “colluding with the Jews.” These long predated the incident on the metro.