According to US media predictions, Democratic congresswoman and “Squad” member Cori Bush lost the primary election in Missouri.
Wesley Bell, a St Louis prosecutor, will instead be the party’s candidate in the state’s first congressional district this November.
Mrs. Bush, a nurse, rose to prominence as an organizer of the Black Lives Matter movement and after taking office in 2021, she was one of the Democratic members of the “Squad,” known for supporting progressive causes.
She has been a vocal critic of Israel’s war in Gaza, with pro-Israel groups spending more than $10m (£7.9m) on efforts to unseat her in the primary.
According to projections from both the Associated Press and NBC News, Mr. Bell is on track to win with 51% of the vote, compared to 46% for Mrs. Bush.
The district is strongly Democratic and Mr. Bell is expected to hold on to the seat in the general election in November.
Almost all of the money spent on the campaign against Mrs. Bush is believed to have come from the American Israel Public Affairs Committee (Aipac). Aipac is a pro-Israel lobbying group that has vowed to spend more than $100 million to undermine progressive lawmakers who have spoken out against the war in Gaza, Politico reported.
In her concession speech, Mrs Bush declared: “All they did was radicalise me, so now they should be scared.”
“Aipac, I have come to destroy your kingdom,” she added.
This is the second defeat for the Squad — a group of nine progressive Democrats in the US House of Representatives — in the 2024 election cycle.
In June, more than $15 million was invested in a successful attempt to overthrow Jamaal Bowmananother Israel critic, from his seat in New York. The figure was the most spent in any House primary in history. Mr. Bowman was ousted just weeks after he was criticized for pull the fire alarm while the House is in session.
Speaking to CBS News, the BBC’s US news partner, ahead of the vote, Mr Bell accused Mrs Bush of “failing to do her job”.
“She doesn’t work with other people and that hurts our county.”
Mrs. Bush defended her record to the newspaper: “My community knows who I am. They know that I will fight for people on the streets.”
Less than two weeks after the October 7 attack, Mrs. Bush introduced a resolution calling for a ceasefire and humanitarian aid.
Attacks by Hamas and other militant groups have left some 1,200 people dead in Israel and another 251 hostages taken in Gaza.
In response, Israel declared a “total siege” on Gaza, cutting off its electricity, food, fuel and water supplies. More than 39,600 people have been killed in Israel’s military campaign in Gaza so far, according to the Hamas-run Health Ministry.
Mrs. Bush also boycotted Israeli Prime Minister Benjamin Netanyahu’s joint address to Congress in July, calling him a war criminal and saying he was leading a genocide. Dozens of Democrats in the House and Senate boycotted Netanyahu’s speech.
In a statement before the vote, Mrs Bush accused Mr Netanyahu of committing “genocide” in Gaza and said Congress was “actively celebrating” his actions.
Mrs. Bush is also under investigation by the Justice Department, the House Ethics Committee and the Federal Election Commission over her campaign spending, primarily over allegations that she improperly paid her husband, a security guard, for protection.
She has previously said any allegations of her misuse of federal money are “completely false.”
Three other US states – Kansas, Michigan and Washington – also hold primaries on Tuesday.
Dan Newhouse, one of the last Republicans to vote to impeach Donald Trump, appears to have won the primary.
Washington state holds a primary election known as a “jungle election,” which allows the top two finishers — regardless of party — to advance to the general election.
Mr. Newhouse, an agricultural scientist who has represented a central Washington district since 2015, faced two Trump-backed candidates — Navy veteran Jerrod Sessler and former nurse Tiffany Smiley.
Early projections of the race show Mr Sessler leading Mr Newhouse, with Ms Smiley close behind – meaning the incumbent could face a tough challenge in November.
Of the so-called “impeachment 10” — Republicans who voted to impeach Trump — only Mr. Newhouse and David Valadao of California remain in the House.
All other pro-impeachment Republicans have left Congress since the 2021 vote or were defeated in primaries.
