Vice President JD Vance is igniting fresh concern among Israel-supporting conservatives after lashing out at a journalist who questioned whether Buckley Carlson, a member of Mr. Vance’s staff and the son of Tucker Carlson, holds antisemitic views.

Conservative journalist Sloan Rachmuth, who is Jewish and a strong supporter of Israel, took to X on Sunday to point out social media postings in which Tucker Carlson’s younger brother — who is also named Buckley — expressed support for Nick Fuentes, the avowed antisemite and Holocaust-denier that Tucker hosted for a friendly, in-studio interview in October.

Identifying “racism and antisemitism” as a “Carlson family trait,” Ms. Rachmuth questioned whether “Tucker’s son Buckley, who serves as JD Vance’s top aide,” is “also a vile bigot.” She argued that “America deserves to know how deep the Carlson family’s ethnic and religious hatred runs.”

Although Ms. Rachmuth’s social media reach pales in comparison to Mr. Vance’s — she has just under 50,000 followers on X, while Mr. Vance has 4.8 million — her line of questioning struck a chord. The vice president reshared her post to deliver a lengthy rebuke.

“Sloan Rachmuth is a ‘journalist’ who has decided to obsessively attack a staffer in his 20s because she doesn’t like the views of his father,” Mr. Vance wrote on X Sunday. “Every time I see a public attack on Buckley it’s a complete lie. And yes, I notice every person with an agenda who unfairly attacks a good guy who does a great job for me.”

He went on to denounce Ms. Rachmuth, who is Jewish, for describing herself in her X bio as a “defender of ‘Judeo-Christian values,'” arguing that it is not “a ‘Judeo-Christian value’ to lie about someone you don’t know.” Mr. Vance said he holds “extraordinary tolerance for disagreements and criticisms from the various people in our coalition” but “zero tolerance for scumbags attacking my staff.”

Mr. Vance, however, did not address whether his 28-year-old deputy press secretary shares his father’s views.

Mr. Vance has called Mr. Fuentes “a total loser” after the 27 year-old influencer insulted the second lady, Usha Vance. He has not, however, issued any criticism of Mr. Carlson, even as the fired Fox News host has slipped from anti-Israel rhetoric to more direct invocation of antisemitic tropes. At Charlie Kirk’s memorial service, with Mr. Vance in attendance, Mr. Carlson described in his eulogy “people in power” in Roman-occupied Judaea “sitting around eating hummus” and plotting the downfall of Jesus of Nazareth. The comment was seen as a “blood libel,” stirring up the centuries-old canard that the Jews were responsible for Jesus’ arrest and execution (the historical record shows that the Romans were entirely responsible).  

Mr. Carlson, during his interview with Mr. Fuentes last month, did not challenge the young man when he raised concerns about “organized Jewry in America.”

Mr. Carlson is believed to have been instrumental in convincing President Trump to choose Mr. Vance for his running mate, a choice that, at the time, was controversial and far from a foregone conclusion. With Mr. Vance widely believed to be the front runner to succeed Mr. Trump as president and head of the MAGA movement, the pro-Israel faction of the conservative movement — along with many Jewish conservatives — have become increasingly concerned.

Indeed, the vice president’s harsh response to Ms. Rachmuth drew criticism from members of his own party who questioned why concerns from a journalist with relatively limited reach triggered such a forceful rebuke while Mr. Carlson’s embrace of antisemitic ideas has not.

A policy analyst at the Middle East Forum, Daniel Pipes, pondered why Mr. Vance responded to Ms. Rachmun by “attacking her rather than answering her question,” he shared on X. “Makes one suspicious, no?” 

At the same time, though, Mr. Vance received support from party members who have similarly refused to disavow Tucker Carlson. “Good for @JDVance — this is disgusting,” wrote former Fox News host Megyn Kelly, who herself has come under increasing criticism for repeatedly defending Mr. Carlson and Candace Owens, a Holocaust denier. “They can’t bring down Tucker so they’re going after his son,” she said. 

Former Florida Representative Matt Gaetz, Mr. Trump’s first pick for attorney general who remains influential in Republican circles, remarked: “Buckley is Awesome!”

The director of the National Jewish Advocacy Center, Mark Goldfeder, said that the children of public figures should not be scrutinized for their parents’ views, though he noted that Tucker Carlson did not extend the same courtesy to the stepson of the Jewish conservative commentator Mark Levin, whom Mr. Carlson attacked at length during a recent podcast episode. Mr. Levin, responding to Mr. Goldfeder’s post, wrote: “Yes, leave the kids alone. Tucker spent an hour trashing my stepson.”

Earlier this month, the vice president drew criticism from Laurie Cardoza-Moore, former head of the Heritage Foundation’s National Task Force to Combat Antisemitism, after he failed to condemn as antisemitic a question posed by a right-wing student activist at a Turning Point USA event in Mississippi.

The incident intensified existing tensions over the Heritage Foundation’s continued backing of Mr. Carlson — a close associate of Mr. Vance — despite his embrace of controversial figures. The controversy peaked last month when Heritage’s president, Kevin Roberts, released a bizarre video statement defending Mr. Carlson as a “close friend” of the foundation and condemning what he termed a “venomous coalition” of critics attempting to “sow division.” He also said Mr. Fuentes should not be de-platformed (Mr. Roberts later apologized under pressure).

Mr. Vance also defended a group of young Republican staffers and activists who traded antisemitic and racist slurs in a group chat that was leaked in October. The messages included references to “gas chambers” and Nazis, with one participant writing “I love hitler.”

Mr. Vance characterized the staffers — whose ages ranged from 24 to 34 — as “kids” who “do stupid things,” he said during an appearance on “The Charlie Kirk Show.” He added: “They tell edgy, offensive jokes. That’s what kids do. And I really don’t want us to grow up in a country where a kid telling a stupid joke — telling a very offensive, stupid joke — is cause to ruin their lives.”