Whatever quarrels one might have with Senator Bernie Sanders, his thinking would seem to be immune from medieval anti-Semitic influence. Yet last month, after Sanders denounced “the Netanyahu government’s extermination of Gaza,” the pro-Israel group AIPAC attacked Sanders’s statement as a “hate-filled rant” and “despicable blood libel.”Extraordinary claims—such as the charge that the Jewish senator from Vermont is anti-Semitic to the point of spreading ancient slanders against his own people—require extraordinary evidence. Yet large segments of the conservative and even centrist wings of the American pro-Israel movement have whipped themselves into such a frenzy of paranoia that they are making accusations like this without much effort at justification.Conflating criticism of Israel with anti-Semitism is not new, but it has exploded in the post–October 7 era, in which the rising menace of genuine Jew-hatred on the left and right alike has been accompanied by a growing chorus of hyperbolic, bad-faith accusations. This dynamic might seem paradoxical, but the two phenomena exist in a natural symbiosis. Anti-Semites often insist they are being targeted merely for criticizing Israel; their defense becomes more effective when many people are, in fact, being called anti-Semitic merely for criticizing Israel.[Yair Rosenberg: America’s anti-Jewish assassins are making the case for Zionism]The hallmark of this style of politics is that, although it does not explicitly state that all criticism of Israel is inherently anti-Semitic, it acts as though that were true. Consider another recent episode. Late last month, The New York Times ran a photo of a child in Gaza, who the accompanying article said was “born a healthy child” but had recently been “diagnosed with severe malnutrition.” Later, it added an editor’s note clarifying that he “also had pre-existing health problems,” which should have been noted in the photo caption.Newspapers make errors from time to time, especially while covering wars, when verifying facts is more dangerous and difficult. Yet some conservatives immediately determined not only that the error reflected an institutional bias against Israel—hardly an indisputable premise, given the anger that the Times has generated on the left for its reporting on such topics as sexual violence by Hamas—but that this bias in turn reflected animus against Jews. “The media were so eager to produce a story about Jews behaving amorally that they dropped all skepticism in the face of a sensationalistic claim from a terrorist group with a known history of lying,” wrote the National Review editor Philip Klein.Noah Pollak, a Trump appointee at the Department of Education, did not even grant that the error was inadvertent, charging on X that the paper had deliberately published a falsehood: “This is a really strange way of saying ‘We ran a front page blood libel claiming Israel is starving a baby to death, but it’s not true and we actually knew it wasn’t true at the time, but it promoted hatred of Jews so we ran it anyway.’” Likewise, Seth Mandel, writing in Commentary, treated the error as an act of anti-Semitic malice: “Pointing to a suffering child and saying ‘the Jews did this’ when in fact the Jews did no such thing is an intentional act.” As with the Sanders episode, none of these critics offered any explanation as to why the Times—a newspaper whose executive editor, along with many staffers, is Jewish—would be institutionally committed to whipping up anti-Semitic animus.The proliferation of the term blood libel as a rhetorical tic is especially revealing. The blood libel is a medieval conspiracy theory that posits that Jews murder Christian children in order to use their blood in religious ceremonies. It was used for centuries to incite murder against Jews. My wife’s grandmother once told me that her mother had a vivid memory of being a child in 19th-century Russia, hiding under a bed and watching a Cossack plant a dead child in her family’s home to blame on the Jews.To claim that Israel murders Arab children for religious ends would be a blood libel. And because anti-Semitic ideas mutate over time, some forms of obsessive hatred of Israel assign the Jewish state an almost demonic place in the imagination. Anti-Semitism can express itself as an inability to process Israel’s actions, whether good or bad, in the terms one would use for other nations.But to the extent that the outrage over civilian deaths in Gaza is not categorically different from that surrounding, say, the American counterinsurgency in Afghanistan, Israel’s critics are treating it as a normal state. Some elements of the contemporary pro-Israel right have refused to accept that. They have, instead, repurposed the phrase blood libel to cast almost any complaint about the Israeli war effort as anti-Semitic. Because arguments about the scope of war inherently revolve around the propriety of violence, this tactic has limitless application.This rhetorical move is striking in its resemblance to the style of the illiberal left. If you identify your own political position with a vulnerable group, you can accuse anybody who disagrees of opposing the group, thus circumventing the need to defend your position on the merits. The most common fallacy associated with this form of backward reasoning is to assume that any argument a bigot might use is bigoted. Because racists oppose affirmative action, its defenders sometimes assume all opponents of affirmative action are racist; likewise, because anti-Semites hate Israel, some of its defenders treat opposition to Israel as presumptively anti-Semitic.In some cases, the homage is explicit. Some campus activists have demanded that pro-Israel Jews receive the kind of protective treatment that university administrators have previously extended to students from, or speaking on behalf of, other marginalized groups. (Others have merely asked that schools fairly apply content-neutral rules to activists who seize common spaces or shout down pro-Israel speakers.) This would be a logical demand if you believe that illiberal discourse norms have benefited minority students and fostered tolerance. But if you believe that they’ve generated resentment without helping their supposed beneficiaries, as members of the pro-Israel right generally do, then it is a strange racket to try to get in on.The Trump administration has turned these illiberal concepts into official government policy. Its higher-education agenda revolves around the use of pretextual charges of anti-Semitism to withhold funding and subject universities to political interference. It has detained immigrant students for criticizing Israel and worked with right-wing activists to target protesters and issue draconian demands for “reform.”How could a movement prone to hair-trigger charges of anti-Semitism identify itself so closely with this administration? President Donald Trump has welcomed an anti-Semitic and even Nazi-curious faction into his coalition, normalizing rhetoric that not long ago would have been disqualifying in a Republican administration. (Kingsley Wilson, a Defense Department spokesperson, has dabbled in anti-Semitic memes, including attacking the memory of Leo Frank, perhaps the most famous victim of anti-Semitic violence in U.S. history.) Trump himself has routinely discussed Jews in crude terms, as money-obsessed and primarily loyal to Israel.In fact, the alliance has a certain logic to it. The pro-Israel right is not so much expanding the definition of what constitutes anti-Semitism as shifting it, so that it covers far more criticism of Israel and far less behavior that would traditionally have fit the bill. After Trump criticized unethical bankers as “shylocks”—drawing a wrist slap from the Anti-Defamation League, which has otherwise supported his campus crackdown—the Commentary editor John Podhoretz wrote on X, “Trump bombed Iran. He can say Shylock 100 times a day forever as far as I’m concerned.”Here Podhoretz is following in the tradition of his father, Norman, who preceded John as editor of Commentary, once an esteemed journal of Jewish thought. Thirty years ago, after Pat Robertson published a conspiratorial book arguing that a tiny sect of “European bankers” had controlled world affairs for decades, Norman Podhoretz defended Robertson from charges of anti-Semitism in a lengthy essay. “In my view,” he wrote, “Robertson’s support for Israel trumps the anti-Semitic pedigree of his ideas about the secret history of the dream of a new world order.”[Michael Powell: The double standard in the human-rights world]At the time, Robertson’s crankish views may have seemed marginal enough that his allies could pretend they were tolerable. The door that Podhoretz cracked open for one nutty televangelist has since swung wide open for hordes of obsessive anti-globalists, Nazi-meme appreciators, and other enemies of the Jews. Building a coalition united by its total indifference to Palestinian human rights requires teaming up with some people who may lack a certain moral refinement when it comes to the Jews. But you go to political war with the coalition you have, not the coalition you wish you had.This alliance harms the Jews in two obvious ways. First, it provides cover for the legitimization of a strain of far-right anti-Semitism that had been frozen out of mainstream political influence since the demise of the “America First” movement at the start of World War II. Second, it weakens the fight against left-wing anti-Semitism by diluting the charge through overuse. Flooding the public square with counterfeit accusations devalues the currency. And allowing the cause to be turned into cover for a crackdown on the left that is at best loosely related to defending Jews inevitably subjects the idea of opposing anti-Semitism to cynicism. The pro-Israel right’s response to that critique is, of course, to label it as anti-Semitic. “Jews are being threatened with consequences for being seen as exercising undue influence over campus life,” writes the Manhattan Institute legal-policy fellow Tal Fortgang.American culture has passed through an era in which elements of the social-justice left sought to shut down opposition to their agenda by branding disagreement as bigotry. Members of the pro-Israel right, who gained power in part by riding the backlash against the excesses of left-wing illiberalism, have now decided to borrow its techniques. Can they truly not imagine that they will generate a backlash of their own?