High-profile Missouri primary threatens to knock out second 'Squad' member Cori Bush

Following New York Rep. Jamaal Bowman's primary defeat at the hands of George Latimer, another member of "The Squad" is at risk of being ousted: Democratic Rep. Cori Bush of Missouri, who is facing a strong challenge from St. Louis County Prosecuting Attorney Wesley Bell in the Democratic primary on Tuesday.

The race catapulted to national attention in part due to the tremendous amount of outside group spending. The United Democracy Project PAC, the fundraising arm affiliated with the American Israel Public Affairs Committee, has spent more than $7 million to challenge Bush, who currently represents a district composed of the St. Louis area, and boost Bell's profile.

This dynamic is reminiscent of Bowman's race, where he and his supporters point to AIPAC's enormous cash flow behind his challenger as a key reason he lost his primary in June. United Democracy Project's spending in Bowman's race helped make it the most expensive House primary in U.S. history.

Asked for comment for this story, Bush's campaign pointed to data showing that it is the second-most expensive House race.

AIPAC's involvement in this primary was precipitated by Bush's critical stance of Israel in how it carried out its war with Hamas, a posture held by many other progressive lawmakers, including Bowman.

Bush has said that Israel is committing genocide in Gaza following Hamas' attacks on Israel on Oct. 7 -- and was supported in calling for a cease-fire by over two dozen local faith and social justice groups, including Jewish organizations, last November.

Bush was condemned by a group of local Jewish organizations, including the Jewish Federation of St. Louis, the St. Louis Jewish Community Center and the St. Louis Rabbinical and Cantorial Association, for her "communication about the recent events in Israel and Gaza," which they described as "insensitive, incorrect, and fanning the flames of antisemitism."

Another group of Jewish clergy endorsed Bell in the month leading up to the primary.

Meanwhile, Bell has aggressively campaigned with the St. Louis Jewish community. According to Jewish Insider, Bell has made Jewish outreach a priority in his campaign.

Sam Crystal, the chief of staff of the Jewish Democratic Council of America, which has endorsed Bell, said he believes that this tactic has been successful.

"That he is not just expressing support for the issues that Jewish voters are prioritizing, but taking the time to actually reach out to Jewish voters in the district and to create relationships with the Jewish leaders, has been a big impact on why he's gained so much support in the district," he said.

Crystal said he believes that this outreach will help Bell defeat Bush. He estimated that Jews make up 2.8% of the district and said that "in close races, those kinds of margins can make the difference, and the Jewish vote will be a part of the winning coalition that delivers victory for Wesley Bell."

Professor Dan Butler, director of Undergraduate Studies in Political Science at the Washington University in St. Louis, stressed to ABC News that Bowman and Bush's races have a great deal of differences, especially when it comes to the impact of the Israel-Hamas war.

"Clearly the war in Gaza is what is behind the donor class here. That's the reason Bush is being challenged," said Butler. "But you don't really see it discussed, in part because I just don't think either candidate has much to gain from it."

Butler said he finds that the conflict here is not between centrism and progressivism, as in New York's primary race, but rather a clash between two progressives "trying to signal who's the right member of the Democratic team to send to Washington."

Even still, Bell's campaign is not without problems of its own.

Bell's decision to run for this seat, and his approach to doing so, have garnered some controversy. In October of last year, he ended a bid for Senate to challenge Bush. In a statement at the time, Devon Moody, Bush's campaign manager, said it was "disheartening that Prosecuting Attorney Bell has decided to abandon his U.S. Senate campaign to become Missouri's first Black senator after less than five months, and has instead decided to target Missouri's first Black congresswoman."

And according to Drop Site News, four months before Bell challenged Bush, he privately assured her that he would not drop his Senate bid to face her. "I'm telling you on my word: I am not running against you. That is not happening," he said on the leaked audio.

Moreover, Bell's progressive bona fides have been challenged. Prosecutor Organizing Table, a watchdog organization formed by several racial justice organizations, accused Bell of not matching his promises of being a progressive prosecutor.

Bell has also received criticism for managing Mark Byrne's campaign for the same seat in 2006. Byrne, who Bell's campaign described as a "longtime friend" despite "differences in political affiliations and positions on many issues," ran as a conservative Republican. Byrne's website said that he intended to "protect the rights of the unborn" and that there is "no greater job for elected representatives than to protect those who cannot protect themselves."

Bell campaign spokesman, Anjan Mukherjee told ABC News that Bell has the "momentum and enthusiasm to win this election, and looks forward to taking his progressive track record to Congress."

Sarah Arkebaur, co-chair of the St. Louis Democratic Socialists of America electoral working group, said that with "who is donating to his campaign, as well as his past work for Republican candidates," Bell "does not live up to [the] moniker" of a progressive.

Arkebaur touted Bush's work in Congress.

"She is non-stop fighting for policies that are crucial for working people," she said. "And we know, from what we've talked to -- people at the doors, doing door-to-door canvassing, on the phones doing phone banks -- that these policies are popular with voters."

Usamah Andrabi, a spokesperson for Justice Democrats, offered a similar message.

"This race is about reelecting a champion for abortion rights, democracy and everyday people -- that has the broad support of local electeds, unions and every reproductive rights group against the same Republican megadonors banning abortion in Missouri and trying to elect Donald Trump in November," he said.

If Bush is unable to defend her seat, Butler, the professor, says her loss will send a clear message.

"If Bush loses, it will send a message to the other Democratic incumbents to be much more careful about criticizing Israel," said Butler.

ABC News' Oren Oppenheim contributed to this report.