Progressive pro-Israel lawmakers and activists are gradually beginning to crack down on extreme voices from the hard left as a range of outspoken anti-Zionist groups have grown increasingly radical amid the ongoing war between Israel and Hamas.

The most high-profile rebuke came on Wednesday morning from Rep. Jerry Nadler (D-NY), the informal dean of the House Jewish caucus, who drew unexpected scrutiny to a far-left group, Jewish Voice for Peace, that has held rallies this week in Washington calling for a ceasefire and accusing Israel of committing “genocide” in Gaza.

“Many have asked me ‘who is Jewish Voice for Peace?,’” Nadler wrote on X, formerly known as Twitter. “Their website says they are ‘proud to be a part of the global, Palestinian-led Boycott, Divestment and Sanctions (BDS) movement,’ which, by its founder’s admission and tenets, seeks to end Israel as a Jewish and democratic state.”

As a long-standing opponent of the BDS movement, Nadler, an old-school progressive who has continued to uphold his support for Israel even amid shifting attitudes on the left, is hardly a natural ally of Jewish Voice for Peace, which helped organize a demonstration at the Capitol on Wednesday where dozens of protestors were arrested while occupying a House office building.

The Anti-Defamation League condemned the protest, which was co-organized with IfNotNow, a like-minded activist group. The two organizations also organized a demonstration on Monday outside the White House at which multiple protestors were arrested.

Nadler’s decision to publicly highlight Jewish Voice for Peace, hours before its protest began on Wednesday on the National Mall, represents a notable shift among progressive pro-Israel Democrats who are now pushing back against far-left organizations that continue to downplay Hamas’ terrorism while decrying Israel’s response to the atrocities.

The congressman said in a statement to Jewish Insider that he and his office had “been asked by other members of Congress, constituents, parents and members of the press corps about JVP,” adding: “I wanted to be sure that people are aware of what JVP itself says about its own connection to the global BDS movement. BDS is firmly rejected by the overwhelming majority of the Jewish community, left, right and center.”

A representative for Jewish Voice for Peace’s political advocacy arm did not respond to a request for comment.

Jake Dilemani, a Democratic strategist who lives in Nadler’s heavily progressive district in Upper Manhattan, estimated that an “overwhelming majority” of the congressman’s constituents would support his approach to the group. “For Nadler to come out and say what he said makes perfect sense,” Dilemani told JI, citing recent polls showing a dramatic uptick in Democratic support for Israel in the wake of the attacks. “People don’t want to pay lip service to the far left anymore.”

“I think that Rep. Nadler’s tweet was eye-opening and very clarifying,” said Sara Forman, who leads the New York Solidarity Network, an advocacy group that seeks to promote pro-Israel positions in state and local races. “Hopefully he’ll provide the moral clarity and cover that other activists need so they can join him in exposing these fringe groups for what they are.”

Rep. Dan Goldman (D-NY), a fellow Jewish Democrat in New York who represents one of the most progressive districts in the country, endorsed Nadler’s approach. The congressman “agrees with Mr. Nadler, the most senior Jewish member in the House, who has spent decades steeped in the nuance of America’s relationship with Israel, our closest democratic ally in the region,” Simone Kanter, a House spokesperson for Goldman, told JI on Wednesday.

In a statement to JI, meanwhile, former Rep. Mondaire Jones (D-NY), a prominent progressive seeking to reclaim his old House seat in a heavily Jewish district in the Lower Hudson Valley, said that he has been “deeply disappointed by organizations and politicians — including some in my own party — who have refused to condemn the atrocities committed by Hamas” two weekends ago. “Terrorism is wrong, and Israel has a right to defend itself.”

Within the House, some pro-Israel lawmakers have recently demonstrated that they are even more willing to speak out against colleagues who have equivocated over the attacks while circulating unverified information about the war on social media, among other things.

On Tuesday, Rep. Debbie Wasserman Schultz (D-FL), a Jewish Democrat and stalwart supporter of Israel, issued a rare admonition of a left-wing House colleague, Rep. Ilhan Omar (D-MN), who was among some lawmakers who had amplified a Hamas-promoted narrative — later discounted by U.S. and Israeli intelligence — blaming Israel for a deadly hospital bombing in Gaza.

“We don’t know the facts,” Wasserman Schultz fired back in social media comments on Tuesday evening. “You have been training your outrage on the wrong party. We do know that Hamas’ hatred is the catalyst.”

Prominent progressive lawmakers also pushed back against online commentators who initially promoted claims that Israel had committed the attack on Tuesday. Sen. Chris Murphy (D-CT) said after a classified briefing on the situation in Israel and Gaza on Wednesday afternoon that he trusted the assessments that Israel was not responsible for the attack.

“I think it’s remarkable that so many people were willing to take Hamas’ propaganda at face value yesterday,” Murphy told JI. “The evidence seems pretty clear that this was not an Israeli operation, and I think it’s pretty disturbing that so many mainstream actors weren’t willing to believe Israel and were willing to believe Hamas.”

Sen. John Fetterman (D-PA), a pro-Israel progressive, went after fellow lawmakers more directly in posts on X. “It’s truly disturbing that members of Congress rushed to blame Israel for the hospital tragedy in Gaza,” he said on Wednesday. “Who would take the word of a group that just massacred innocent Israeli civilians over our key ally?”

That question speaks to a broader sense of disenchantment among many progressive Jewish activists who have voiced disappointment with the far left over its response to the conflict. “It seems pretty clear to me that most of my fellow progressive Jews have been very frustrated,” Oren Jacobson, a progressive Jewish activist in Chicago, told JI. “I haven’t spoken to a single person who is out there fighting the occupation who has said to me, ‘I’m OK with what’s going on with the far left.’”

In an interview, Jacobson said he has been “shocked by the lack of empathy and concern that has been demonstrated for not just Israelis but the entire global Jewish community” since the attacks. Referring in particular to Jewish Voice for Peace and IfNotNow, whose initial statement on Hamas’ attacks accused “Israel’s system of apartheid” of provoking the massacre, he said it has now become “abundantly clear that those two organizations just do not speak for the overwhelming global Jewish community right now.”

A spokesperson for IfNotNow, Matan Arad-Neeman, did not address a request for comment regarding Jacobson’s assessment. “As many of us mourn loved ones who were killed by Hamas’s attack,” he said in an email to JI, “thousands of Jews are coming together this week to take action to call for a ceasefire, a release of Israeli hostages, and to prevent a looming genocide against Palestinians in Gaza.”

Joe Vogel, a Jewish Democrat and state legislator running for Congress in Maryland, cautioned that statements from IfNotNow and Jewish Voice for Peace should “be viewed through the prism of who they are: fringe organizations that are far, far outside of the mainstream views of American Jews writ large.”

“That is why I encourage folks not to tokenize them or their views in order to portray that they are somehow representative of the larger community,” he said in a text message to JI on Wednesday. “As you can see from their statements, they fail to offer a full-throated condemnation of Hamas, shamefully pinning all the blame on Israel for the deadliest massacre of Jews since the Holocaust.”

Bill de Blasio, the former mayor of New York City and a staunch supporter of Israel, echoed that view. “There’s no evidence I’ve ever seen that suggests, outside of certain college campuses and certain very narrow elements of the far left, there’s any lack of energetic support for Israel,” he said in an interview with JI, even as he added that “there should be no one who fails to condemn” Hamas’ terrorist attacks.

Far-left voices weighing in on the conflict with insensitive or divisive rhetoric are “invalidating their position and alienating a lot of people who might want to hear from them otherwise,” de Blasio argued. “It does not serve their cause.”

Chris Coffey, a Democratic strategist in New York, said that the hard left has “very much misread the moment,” alluding to a recent Times Square rally promoted by the Democratic Socialists of America that drew widespread criticism for supporting Hamas. “This is a watershed moment for support of Israel,” he told JI. “If you can’t condemn terrorists and call for the release of innocent Jewish children, taken in a sneak attack, then you can’t call yourself pro-Israel.”

Despite the divisions, some progressive pro-Israel activists say the backlash to far-left fringe groups has been clarifying.

“There continues to be a space for Zionist Jews on the left, of course — and we’ve felt more solidarity and received more vocal support than ever before,” Amanda Berman, the founder of Zioness, told JI. “The splintering between those with conscience and humanity, and those glorifying and celebrating evil, could potentially have long-lasting positive consequences for a progressive movement that claims to care, first and foremost, about human rights and dignity.”

Additional reporting contributed by JI’s Capitol Hill reporter Marc Rod.