Cori Bush and Wesley Bell are contesting a rematch in the Democratic primary for Missouri’s 1st District on Tuesday. The race highlights the party’s internal debate over U.S. policy toward Israel. The American Israel Public Affairs Committee’s super PAC, United Democracy Project, has spent at least $2.1 million on ads supporting Bell, according to ad‑tracking firm AdImpact, and Bell’s campaign has added more than $2 million, with New Democrat Majority contributing an additional $700,000, bringing total outside spending to over $4.8 million while Bush’s campaign has spent less than $200,000. A July AP‑NORC poll found that about half of Democrats believe Israel has committed genocide against Palestinians, a claim denied by both the Israeli and U.S. governments. Progressive candidates in Colorado, New York and elsewhere have used similar criticism of Israel to win primary contests against establishment opponents, a trend some analysts describe as the ‘Mamdani effect.’ Bell has secured endorsements from House Minority Leader Hakeem Jeffries and the Congressional Black Caucus PAC. He says he supports campaign finance reform and opposes singling out individuals for political participation. In an interview he said he can both support and criticize allies, noting that he does not favor Israeli Prime Minister Benjamin Netanyahu but believes the United States should stand with its allies. Bush is backed by the Democratic Socialists of America, Senator Bernie Sanders and Representative Rashida Tlaib. Bush said the contest is about the affordability and peace of every person in the country, and that her opponent is funded by AIPAC. Usamah Andrabi, a spokesperson for Justice Democrats, said the nationwide ideological fight reflects a base that believes the party establishment is unable to confront Donald Trump and Republican extremists. The outcome of the St. Louis primary will indicate how the Democratic Party’s internal debate over Israel and other issues will shape future elections.