By Andrew Hay

Dec 22 (Reuters) - Over a dozen employees have left jobs at the Heritage Foundation or were fired in recent days, according to the influential right-wing U.S. thinktank, as it grapples with allegations from former supporters that it has aligned itself with those accused of antisemitism.

In a statement about the resignations and firings on Monday, Heritage Foundation Chief Advancement Officer Andy Olivastro said a handful of staff had chosen "disruption" and "disloyalty."

He said the think tank "has always welcomed debate, but alignment on mission and loyalty to the institution are non-negotiable."

The foundation has been caught up in a firestorm of accusations and counter-accusations that began when former Fox News host Tucker Carlson interviewed Nick Fuentes, a self-described Christian nationalist, in October. The interview focused on their mutual opposition to U.S. support of Israel, a view at odds with that of many conservatives.

Some supporters of the foundation have said it should distance itself from Carlson, characterizing the journalist's views as antisemitic. But Kevin Roberts, the foundation president, has continued to personally back Carlson, who he says is a friend. Carlson strongly rejects accusations of antisemitism.

One of those who resigned this week was Josh Blackman, a law professor who contributed to Project 2025, a hard-right policy initiative overseen by the Heritage Foundation. In a resignation letter posted online, he blamed Roberts for making Heritage's brand "toxic."

"You aligned the Heritage Foundation with the rising tide of antisemitism on the right," said Blackman, who edited the group's Guide to the Constitution publication.

In an October 30 video defending Carlson, Roberts said a "venomous coalition" was attacking the prominent podcaster over his interview with Fuentes. Roberts said conservatives should feel no obligation to support any foreign government no matter how great the pressure from "the globalist class."

He later apologized for his use of the term "venomous coalition," which he said Jewish colleagues understood to be an antisemitic trope. But he said he refused to "cancel friends" like Carlson.

Speaking at a November 5 townhall meeting of foundation staff, Roberts said his intention was not to endorse Fuentes, who he called "an evil person," but to "convert" some of his audience of several million people, without giving further details.

In a leaked video of the townhall, one Heritage staffer said Roberts was right to support Carlson, as Gen-Z had an increasingly unfavorable view of Israel. Two others said Carlson was an "antisemite" who the foundation should disavow.

Three Heritage Foundation board trustees have already resigned over the issue.

Robert George, a Princeton law professor, resigned in November over Roberts' refusal to retract his October 30 video. Shane McCullar, a former McDonald's Corp executive, resigned earlier this month, along with Abby Spencer Moffat, CEO of the Diana Spencer David Foundation, one of Heritage's largest donors. Both cited the foundation's failure to condemn antisemitism, according to resignation statements reported by Mediaite.

Advancing American Freedom, a conservative advocacy group critical of U.S. President Donald Trump's dominant MAGA movement and led by former Vice President Mike Pence, said in a statement on Monday that 13 former Heritage staffers had joined it.

For some remaining Heritage staff, recent staff departures were driven more by Republican Party jockeying than antisemitism or Israel.

"These resignations have a lot more to do with 2028 than it does with anything else," Heritage fellow Robby Starbuck posted online. "One group wants a return to the Pence/Ryan GOP and the rest want to MAGA with @KevinRobertsTX."

(Reporting by Andrew Hay in New Mexico, Editing by Rosalba O'Brien)

((andrew.hay@thomsonreuters.com))