Elon Musk, one of the world’s richest men who is now most famous for running the website X, formerly known as Twitter, has a new excuse for the company’s shaky performance since he bought it last year. The problem, according to Mr. Musk, is the Jews.

In an outburst on his platform on Monday, Mr. Musk claimed — without presenting any evidence — that ad revenues on Twitter are down 60 percent “primarily due to pressure on advertisers by @ADL”— the Anti-Defamation League — which he said “has been trying to kill this platform by falsely accusing it & me of being anti-Semitic.”

While the website has long had a reputation as a cesspool for lies, hate speech and a significant neo-Nazi user base, under a former chief executive officer, Jack Dorsey, Twitter had begun to take steps to ban the most provocative and openly racist and antisemitic users. A 2018 report by the ADL noted that 4.2 million antisemitic tweets had been shared or re-shared on the platform in the previous year, before Twitter’s ban on extremist accounts took effect. Mr. Musk largely reversed those policies under the aegis of free speech. Thanks to the reinstatement of extremist accounts — and a new algorithm which prioritizes posts from “verified” users who have forked over $8 a month to the company — X/Twitter now functions as a bullhorn for the most toxic elements of the white nationalist right.

Mr. Musk also blamed a collapse in the company’s value — estimates place the company’s current worth at roughly one-third the $44 billion Mr. Musk paid for it — on the ADL, saying that he was considering legal action against the ADL and signaling that he supported banning the organization from X.

Mr. Musk insists that his claims are not antisemitic and that he harbors no animus toward the Jews; still, over the past week he has repeatedly launched personal attacks against the ADL head, Jonathan Greenblatt, accusing him of lying about the ADL’s political influence.

There is a long history of far-right groups attacking the ADL for its alleged “smears.” In the late 1950s Russell Maguire, the owner of the right-wing American Mercury magazine, claimed Jewish groups were falsely smearing him and his publication as antisemitic — and, like Mr. Musk, suggested they were organizing a boycott against him. A few years later, in the mid-1960s, Robert Welch, the leader of the far-right John Birch Society, similarly claimed that the ADL was unfairly smearing his organization’s reputation by alleging it was harboring anti-Semites in its ranks.

The ADL was certainly critical of both men — but for good reasons. Mr. Maguire was, in fact, a committed antisemite. He endorsed the authenticity of the infamous antisemitic tract “The Protocols of the Elders of Zion” in his magazine. Mr. Welch, in large part due to pressure from the ADL, was forced to purge the John Birch Society of its most outspoken antisemites in 1966. Considering that Mr. Musk has reinstated and retweeted a number of openly antisemitic and white nationalist accounts since acquiring the website, his attacks on the ADL are very much in keeping with this tradition.

The Anti-Defamation League is not the only organization that monitors far-right speech, nor has it been alone in drawing Mr. Musk’s ire and that of the online far right on Twitter. The Southern Poverty Law Center, founded by civil rights activists in the 1970s, employs a bevy of researchers to monitor and catalog right-wing extremism and has long been the target of attacks by neo-Nazis and white supremacists, and yet the S.P.L.C., a nonsectarian organization, has not been singled out by Mr. Musk.

Part of the reason is that the ADL, until relatively recently, was ambivalent — even supportive — of Mr. Musk. In 2022 Mr. Greenblatt of the ADL praised the billionaire entrepreneur. In comments on CNBC, Mr. Greenblatt called Mr. Musk an “amazing entrepreneur, an extraordinary innovator. He’s the Henry Ford of our time.”

Henry Ford, of course, became famous as the creative genius behind the Ford Motor Company. And, like Mr. Musk, Mr. Ford was a veritable celebrity. In the same way that Mr. Musk’s fanboys on Twitter gush about how his company SpaceX will lead humanity into a cosmic future, Mr. Ford was seen as the apostle of industrial modernity. Joseph Stalin sought out experts from the Ford Motor Company to help industrialize the Soviet Union in the late 1920s. Aldous Huxley dated the calendar in his 1932 dystopian novel “Brave New World” “A.F.” — “After Ford.”

Mr. Ford was also — next to Charles Lindbergh — one of America’s most infamous antisemites of the 20th century, and Mr. Greenblatt was pilloried by liberal and left-wing critics for failing to note this.

Despite Mr. Greenblatt’s tone-deaf lauding of Mr. Musk as the second coming of Henry Ford, the ADL has been justifiably concerned with monitoring Twitter as one of the major global forums for antisemitism since Mr. Musk’s takeover. Twitter’s historical free-for-all approach to speech, while it has allowed for previously marginalized voices to be major players in media narratives, has also allowed for new platforming opportunities for open antisemites and racists, hitherto confined to websites for true believers. Twitter was not the only social media platform to flirt with extremism — Facebook infamously became a vector of disinformation during the 2016 election — but it was unique in its power to shape media narratives.

What explains Mr. Musk’s questionable decision making? It does not take much of a leap to imagine that an immensely wealthy businessman — one who strongly believes in his own messianic mission to uplift humanity and who is facing intense and sustained public criticism over his politics and business acumen for the first time in decades — might conclude that nefarious forces are at work to undermine him. What separates this simple scapegoating from full-blown conspiracism is the sense one gets from Mr. Musk and his acolytes that criticism of him imperils the utopian future of mankind. That, combined with the fact that Mr. Musk has been consistently boosting far-right, white nationalist, and antisemitic accounts on Twitter since the beginning of his tenure, effectively melds his sense of victimhood with the conspiratorial antisemitism of the most toxic elements of the right.

X, née Twitter, despite losing significant value due to Mr. Musk’s incompetence and having to contend with rivals like Meta’s Threads, is still the most influential social media platform in shaping the national news narrative. As Kanye West, himself no stranger to making unhinged antisemitic statements, has said, “No one man should have all that power.”

The Republican Party already has a serious problem with some campaign staffers openly trafficking in antisemitic and white nationalist speech. Mr. Musk scapegoating the Jews for his own catastrophic business decisions regarding his management of one of the most influential social media platforms in the world will only add fuel to the fire.

David Austin Walsh (@DavidAstinWalsh) is a postdoctoral associate at the Yale Program for the Study of Antisemitism and author of the forthcoming book “Taking America Back: The Conservative Movement and the Far Right.”

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