Progressive lawmakers who have condemned Israels assault on Gaza are demanding Democratic leadership do more to combat a multimillion-dollar election-year backlash funded by the American Israel Public Affairs Committee, Washingtons most powerful pro-Israel group.

Several House incumbents, including some of the partys rising progressive stars, are facing primary challengers funded by AIPAC, which has raised millions from Republicans. The three largest individual donors to its super PAC, United Democracy Project, are longtime Republican supporters who have given the party millions of dollars, its latest disclosures showed.

Rep. Cori Bush (D-Mo.), whose challenger is courting pro-Israel donors, called for Democratic primary candidates to reject AIPACs help outright.

Its simply not good enough for Democrats to run against Donald Trump and his MAGA extremist allies while running toward right-wing, dark-money groups like AIPAC, Bush said.

Other incumbents are warning that by doing nothing, the party is allowing GOP mega-donors to try to dictate the winners of Democratic primaries.

Its a Trojan horse its a way to smuggle Republican money into Democratic primaries, Rep. Mark Pocan (D-Wis.), a vehement AIPAC critic, told HuffPost. People should have to answer for taking that toxic money.

AIPAC is the premier lobbying group protecting the United States political and military alliance with Israel. It has held bipartisan sway for decades. But Israels devastating offensive in the Gaza Strip has placed its deep ties to the Democratic Party under growing strain.

Plenty of special interests donate to one candidate over another. But no outside group has made it its mission to hand-pick primary winners with the same relentlessness as AIPAC and its affiliates. In 2022, United Democracy Project spent $26 million targeting just eight congressional candidates who publicly repudiated Israels treatment of Palestinians, helping to defeat six of them.

AIPAC has exclusively targeted progressive Democrats and has never inserted itself into a Republican primary.

This year, the group is fixated on unseating members of the so-called Squad, including Reps. Bush, Ilhan Omar (D-Minn.), Summer Lee (D-Pa.) and Jamaal Bowman (D-N.Y.), who are among the most outspoken critics of Israels strikes on Gaza. Donors associated with the group have reportedly offered to raise up to $20 million for candidates willing to challenge Rep. Rashida Tlaib (D-Mich.), the only Palestinian American member of Congress.

Theyre trying to make our elections auctions, Pocan said.

In recent weeks, one lawmaker facing AIPAC attacks canceled their payment of quarterly dues that all Democratic members of Congress pay to the Democratic Congressional Campaign Committee, a campaign aide told HuffPost, in order to conserve cash for the onslaught.

I dont know how anyone running as a Democratic primary challenger could possibly want to be on the same side as Donald Trump and his January 6 insurrectionists, said Lee in a statement as she faces another primary challenger after AIPAC spent $4 million trying to defeat her in 2022. Their Republican billionaires want to use Israel as a political football to divide & distract us from being able to talk about the issues the majority of our constituents care about.

Progressives have repeatedly pleaded with House Minority Leader Hakeem Jeffries (D-N.Y.) and other party leaders behind closed doors to stand up for incumbents who are coming under fire.

Jeffries endorsed Lee earlier this month. In 2022, a political action committee Jeffries started made modest donations to her and other candidates as a signal of his support .

But candidates facing the AIPAC onslaught want more.

Bush faces a primary challenge from St. Louis County prosecutor Wesley Bell, who abruptly dropped a months-long Senate campaign because he was motivated to run by a need to stand with our allies, and Israel has always been an ally, he told The Washington Post .

We have had these conversations [with leadership], and personally Ive just never gotten to a place where weve heard theres going to be some change, Bush told HuffPost. We have heard them say, We get it. I havent heard any conversation that, as a caucus, were going to say, No, were not going to continue to be an ally with AIPAC unless they do x.

Party leaders have taken shots at outside groups without naming AIPAC and, according to Pocan and other sources, have privately taken AIPAC to task for influencing its primaries.