Rep. Wesley Bell (D-Mo.) defeated former Rep. Cori Bush in his primary on Tuesday, thwarting an attempt by left-wing groups, including the Democratic Socialists of America, to avenge Bush's 2024 loss. Why it matters: It's a win for the Democratic establishment in an election cycle where triumphs against left-wing insurgents have been few and far between. Bell's win was propelled in part by United Democracy Project, the super PAC arm of AIPAC, which spent more than $3 million to thwart Bush's comeback, according to Federal Election Commission filings. Bell was also endorsed by House Democratic leadership and the Congressional Black Caucus, while Bush had the backing of Sen. Bernie Sanders (I-Vt.) and left-wing groups such as DSA and the Justice Democrats. Driving the news: Bell led Bush by 45 percentage points with about a quarter of precincts reporting as of Tuesday evening, with the Associated Press projecting he would win the nomination. Bush, a former progressive organizer, represented the St. Louis-based seat from 2021 to 2025. She lost her 2024 primary to Bell amid a campaign finance scandal and roughly $9 million in AIPAC ad spending. By the numbers: In addition to UDP, the super PAC of the center-left New Democrat Coalition and the American Bridge-affiliated Project 218 spent another $1.1 million and $250,000, respectively, supporting Bell. Bush was supported by a little over $200,000 in collective outside spending from progressive groups, including MoveOn and the Working Families Party. Bell also out-raised and outspent Bush, bringing in nearly $3.6 million and spending more than $2.9 million as of July 15, compared with Bush's $1.3 million in fundraising and $1.2 million in spending. What's next: Bell is all but certain to win in November — former Vice President Kamala Harris carried the district by 57 percentage points in 2024.