The remarks by podcaster Tucker Carlson at the memorial service for conservative activist Charlie Kirk are a baleful reminder that the right is just as susceptible to the plague of antisemitism as the left. The memorial, attended by 90,000, was on the whole a wonderful reminiscence suffused with the religious faith that Kirk and his wife Erika elevated. It will no doubt be remembered for years to come. Mr. Carlson’s contribution, though, was execrable.

Mr. Carlson has made obsessively baiting Israel central to a worldview that also genuflects to President Vladimir Putin. He ascended to the rostrum at Arizona and compared the murder of Kirk to the betrayal of Christ — what Mr. Carlson calls his “favorite story ever.” He explains how Jesus starts “telling the truth about people … and they hate it and they just go bonkers.” These unnamed people — hint, it’s the Jews — plot to “shut this guy up.” 

Mr. Carlson imagines a “scene in a lamp lit room with a bunch of guys who are sitting around eating hummus” and who decide that they “must make him stop talking.” There is always one person, Mr. Carlson speculates, who proposes, “Why don’t we just kill him. That’ll shut him up. That’ll fix the problem.” Mr. Carlson then unleashed a laugh that can only be described as maniacal before gloating that “it doesn’t work that way.”

Mr. Carlson’s remarks appear to allude to a conspiracy theory that circulated online in the hours and days after Kirk’s murder that assigned to Israel blame for the assassination. So pervasive were these falsehoods that Prime Minister Benjamin Netanyahu, in videotaped remarks, was moved to denounce them as “disgusting rumors.” The premier insisted, “This is insane. It is false. It is outrageous.” Also illogical — Kirk was a supporter of Israel.

Antisemites of every stripe certainly heard the tune. A supporter of Hamas and Hezbollah, Jackson Hinkle, reposted the clip and called it a “mic drop.” Quds News Network hailed the suggestion of “Israeli involvement in Charlie Kirk’s death.” The leader of the estimable Foundation for Defense of Democracies, Mark Dubowitz, accused Mr. Carlson, whose father supported Israel, of working “to spread antisemitic blood libels.”

Never mind that nobody at Jerusalem 2,000 years ago would have been eating hummus — the dish is first attested to in a 13th century cookbook from Syria. Mr. Carslon’s intent is to summon the specter of the ancient accusation that the Jews killed Jesus. That libel was the cause of untold violence and persecution of all stripes against Jews for hundreds of years. It is an eternal stain on the same faith that Mr. Carlson professes.

Credit goes to Mr. Trump for listing “Tel Aviv” as one of the places where Kirk will be mourned. We get that the Republican Party under the 47th president is a rambunctious big tent. It’s long since become clear that Mr. Carlson is part of a dark chorus of paranoid antisemitism on the right. Allowing Mr. Carlson, though, to speak from the same stage as the high officers of the Republic was a mistake.

Mr. Netanyahu reports receiving a letter from Kirk detailing, “One of my greatest joys as a Christian … is advocating for Israel and forming alliances with Jews” — in short, the opposite of Mr. Carlson’s sensibilities. Senator Ted Cruz testifies that the “very last conversation” he had with Kirk “was how deeply concerned he was about the rising, toxic wave of antisemitism on the right.” It was one of Kirk’s most important points.