Fuentes despised Kirk for his support of Israel, and, more broadly, for his efforts to marginalize Fuentes’s gleefully racist and fascist brand of politics. In 2019, seeking to expose Kirk as “anti-white” and a “fake patriot,” Fuentes organized his army of young fans — known as Groypers, after a variant on the alt-right Pepe the Frog meme — to flood events held by Kirk’s organization, Turning Point, and ask hostile questions. At one, they drove Donald Trump Jr. off the stage.

After Kirk was murdered, Fuentes, perhaps fearing he’d be blamed, disavowed violence. But he continued his attacks on Turning Point and accused Kirk’s widow, Erika, of being happy her husband was dead. “I am getting this vibe from her that she’s very fake,” he said.

Even as Fuentes defamed Kirk’s widow, powerful conservatives were engaged in a nationwide campaign to canonize Kirk and destroy progressives who maligned him. Guest-hosting Kirk’s podcast, JD Vance urged listeners to report people celebrating Kirk’s death to their employers. In such an atmosphere, one might think that Fuentes’s stock on the right would have fallen. Instead, it’s risen higher than ever, revealing a seemingly unstoppable ratchet of radicalization on the right.

If you’re not familiar with Fuentes’s ideology, he helpfully distilled it on his streaming show, “America First,” in March. “Jews are running society, women need to shut up,” he said, using an obscenity. “Blacks need to be imprisoned for the most part.” His sneering, proudly transgressive attitude has made him a hero to legions of mostly young men who resent all forms of political gatekeeping. The conservative writer Rod Dreher, a close friend of Vance, warned, “I am told by someone in a position to know that something like 30 to 40 percent of D.C. G.O.P. staffers under the age of 30 are Groypers.” The figure is impossible to check, but it captures a widespread sense that Fuentes’s politics are ascendant.

Fuentes reached a career high last week when he was invited onto Tucker Carlson’s podcast, one of the most popular shows in the country. Carlson gently took issue with a few things Fuentes has said, especially the idea that Jews as a whole are responsible for the sins of Israel and neoconservatism. “I feel like going on about ‘the Jews’ helps the neocons,” Carlson said at one point. But their two-hour conversation was overwhelmingly friendly. Carlson seemed to presume that they were on the same side; his disagreements with Fuentes were mostly about means, not ends.

Conservatives who detest antisemitism were shaken by the interview. They were even more alarmed when Kevin Roberts, president of the Heritage Foundation — long a bastion of the conservative establishment — defended Carlson. “The Heritage Foundation didn’t become the intellectual backbone of the conservative movement by canceling our own people or policing the consciences of Christians,” he said in a video, describing Carlson’s critics as a “venomous coalition” who are “sowing division.”

These comments led to an uproar among some of Heritage’s donors, staff members and supporters, and Roberts attempted to quell it by denouncing Fuentes. But he still seems to think that Carlson was right to give him a hearing. In a message to the Heritage staff obtained by National Review, Roberts rejected “censorship and purity tests,” writing, “Canceling one person today guarantees the purge of many tomorrow.”

Trump all but annihilated that willingness, and many MAGA intellectuals now see Buckley’s quarantine as a mistake. Laura Field, in her excellent new book “Furious Minds: The Making of the MAGA New Right,” quotes the writer and activist Charles Haywood calling Buckley a “Judas” who “led the American Right into a box canyon, swiftly spiking any gun that seemed as if it might be effective in the war waged by the Left on decent America for over a hundred years.”

Not all conservatives embrace the idea of “no enemies to the right” — Dreher has written powerfully against it — but it’s become a significant current in our politics. When Politico reported that several Young Republican leaders took part in a racist group chat that included praise for Hitler, some in the party were appalled, and a few of the participants lost their jobs. But Vance defended them as “kids” whose lives shouldn’t be ruined for telling jokes. (Some were in their 30s.) Within certain MAGA circles, to criticize someone for being too racist or reactionary is a betrayal, signaling an acceptance of the very liberal morality that the movement’s vanguard seeks to destroy.

Kirk, who came of age in the pre-Trump conservative movement, was still sometimes willing to police boundaries. But in the wake of his killing, there’s surprisingly little sense on the right that that part of his legacy should be upheld. Rather, prominent voices insist that Kirk’s murder necessitates the final loosening of all remaining restraints. “I cannot ‘unite’ with the left because they want me dead,” the influential podcaster Matt Walsh posted after Kirk’s death. “But I will unite with anyone on the right.”

Vermeule is a cultivated man who, as Field writes, is part of a movement that “thinks it has a monopoly on things like ‘the true, the good and the beautiful.’” Yet however lofty his rhetoric, its moral logic leads inexorably to Groyperism, and the elevation of Fuentes, Kirk’s foe, into his successor.