The Squad could lose a second member. It’s not the warning sign you may think.

NEW YORK — Pro-Israel and centrist groups dealt a blow to the left by taking out Rep. Jamaal Bowman in a Democratic primary. And they already have a next target in mind. But it may be difficult for moderate forces to gain wider momentum this year against left-wing Democrats, many of whom are heavily armored against primary challenges.

The American Israel Public Affairs Committee, the country’s leading pro-Israel group, made Bowman’s race against moderate Democrat George Latimer the most expensive House primary in history. And now Rep. Cori Bush (D-Mo.), another member of the progressive Squad, could also be ousted when she faces St. Louis County prosecutor Wesley Bell in an Aug. 6 primary.

Bowman’s loss is a warning sign for the political left, as pro-Israel groups work to mobilize Jewish voters and allies to unseat critics of Israel and force the party back to the middle. But both Bush and Bowman have been weighed down by serious political weaknesses that set them apart from other progressives — and make them far more vulnerable to groups like AIPAC.

“Both Bowman and Cori Bush are pursuing personal agendas that have hurt their communities,” Patrick Dorton, spokesperson for AIPAC super PAC United Democracy Project, said in an interview. “We saw in New York that people were turned off by Bowman’s national agenda; the same thing is happening in St. Louis.”

Exploiting the internal Democratic Party divide over Israel and the war in Gaza, AIPAC and allied groups have pledged to oust left-leaning members of the Squad this year, backing moderate candidates who have been more supportive of Israel. Both AIPAC and Democratic Majority for Israel, a separate pro-Israel group, signaled minutes after the race was called that Bowman’s loss was “a major victory for the Democratic mainstream.”

The spending barrage played a big role in ousting Bowman — but he was weakened even before any of his rivals spent a dime against him. He pleaded guilty to a misdemeanor charge for pulling the fire alarm in a House office building during a government funding vote last year and suggested over a decade ago that 9/11 was a conspiracy. Plus, Latimer is a well-known and popular local figure , a strong foil for an incumbent who faced accusations of not being attuned to local issues.

Bowman unseated 16-term Rep. Eliot Engel in 2020 in a district that includes wealthy suburban communities along the Long Island Sound and urban areas where Black and Latino voters are the majority. Latimer’s allies believe the district, with its large Jewish population and Bowman’s comparatively weak ties to community leaders, made the incumbent unusually susceptible to a challenge.

“It can be duplicated in some parts of the country,” Amy Paulin, a Democratic state assemblymember and Latimer supporter, said of Tuesday’s results. “You need the right candidate.”

Bush similarly has personal issues that make her politically vulnerable, including a federal investigation she’s facing for campaign spending on private security, including payments to her now-husband.

While the outside groups are going after candidates with baggage, they’re skipping other races where their investments might not make much of a difference. In March, Mark Mellman, the chair of the pro-Israel group the Democratic Majority for Israel PAC, told POLITICO that DMFI is targeting Bowman and Bush “not just because” of their stance on Israel, “but because they also have other problems, additionally.”

“Defeating people like Jamaal Bowman and Cori Bush sends a message that the Democrats aren’t an extreme party,” Mellman said in an interview Wednesday. “Getting rid of these people, stopping more of them coming into the Congress, strengthens the U.S.-Israel relationship.”

Notably, both AIPAC and DMFI passed on spending in Rep. Summer Lee ’s (D-Pa.) race, the first member of the Squad to face a primary challenge this year. Rep. Alexandria Ocasio-Cortez (D-N.Y.) crushed her primary opponent on Tuesday. And most members of the Squad didn’t even draw a challenger, including Reps. Ayanna Pressley (D-Mass.), Rashida Tlaib (D-Mich.) — though there was a recruitment effort — and Greg Casar (D-Texas). Neither group has indicated that they’re jumping into Rep. Ilhan Omar ’s (D-Minn.) primary, where she faces Don Samuels, a former member of the Minneapolis City Council who came close to unseating her in the midterms. Pro-Israel groups mostly sat out Omar’s 2022 contest , which drew ire from Samuels. When he launched his bid for the rematch last year, he told Jewish Insider that he has not been in touch with AIPAC .

Bush on Wednesday slammed the heavy spending in Bowman’s race.

“These same extremists are coming to St. Louis,” she said in a statement. “They are bankrolling a faux-progressive, former Republican campaign operative to buy our deep blue Democratic seat. But let me be clear: St. Louis will not be silenced or sold out.”

Bush’s allies have sought to tie Bell, a progressive prosecutor, to Republicans. His campaign pushed back: “Bush is desperate to talk about anything other than how she has failed the people of Missouri’s 1st congressional district,” adviser Anjan Mukherjee said in a statement. “Wesley has a proven progressive track record of bringing people together and delivering results, and that's exactly how he will represent this district in Congress.”

AIPAC rarely telegraphs its targets in advance. In April, the group told POLITICO it was monitoring 15 to 20 races on both sides of the aisle, and in addition to Democrats, UDP has spent against Republicans in GOP primaries. But Bowman and Bush’s cases were different, as AIPAC backed Latimer and Bell in January and February, respectively — months ahead of the election.

UDP hit the air with its first offense against Bowman in May. In the span of just a little over five weeks, it dropped a whopping $15 million, a staggering sum that was due in part to the expensive New York City media market.

It’s beginning its onslaught against Bush even earlier.

UDP’s opening ad in the Missouri race came at the end of May, months before the August primary. The group has already booked $2.5 million on ads, according to ad tracker AdImpact, a sum that’s only expected to increase. (The St. Louis media market is not as expensive as New York City.)

Like its ads against Bowman and in many other races , UDP rarely talks about Israel or the war in Gaza. The group told POLITICO last month that it runs ads “on the issues voters are most focused on,” and will run ads on Israel “where it makes sense.” Its first TV spots in Bush’s race highlighted Bell’s biography and experience . Last week, it hit Bush with the same accusation it had for Bowman: She doesn’t support President Joe Biden, pointing to her opposition to the bipartisan infrastructure bill and debt ceiling deal.

That’s a slight that, like Latimer , Bell has echoed. “You can't just cheer from the bleachers or grandstand for yourself,” he says in his opening ad . “You’ve gotta be a team player that stands with President Biden and against the dangerous hate-filled agenda of Donald Trump.”

Liberal activist organizations are now rushing to bolster Bush.

“We need leaders like Cori Bush not just to win in August, but crucially, to win in November, because the Democratic Party needs — more than ever — Black and brown voters, progressive voters and young voters,” Usamah Andrabi, a spokesperson for the Justice Democrats, said in an interview.

Even though there are other factors that contributed to Bowman’s overwhelming loss, his ouster could prove to be effective fodder as progressives ramp up their attacks against AIPAC — including calling the group, which isn’t necessarily well-known by the broader electorate, out by name .

Bush’s opening spot referenced an article saying that AIPAC is “spending heavily” to beat her, accusing “MAGA Republicans” of “trying to buy this congressional seat.” (AIPAC receives donations from both sides of the aisle, but is the biggest source of Republican money flowing into competitive Democratic primaries this year.)

“Let’s imagine that they succeed in defeating Cori Bush,” said Ana María Archila, co-director of the New York Working Families Party, “that still doesn’t accomplish what they’re trying to accomplish, which is to make people abandon the idea of a cease-fire.”