First-term Rep. Brandon Williams, R-N.Y., is projected to lose his re-election bid in a blow to Republicans' effort to keep the House majority.
Williams was widely seen as the most vulnerable House Republican incumbent this cycle. While his loss was not unexpected, it could signal the tide is turning against the Congressional GOP.
He was defeated by New York state Sen. John Mannion, a moderate Democrat, according to Associated Press projections.
As of late Tuesday evening, when AP called the race, House Democrats were projected to win a total 108 seats so far, compared to 164 projected victories for Republicans.
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Rep. Brandon Williams, left, and Democratic challenger John Mannion, right, faced off in one of the most closely watched races. (AP)
House Democrats' campaign arm and its allies poured an enormous amount of resources into flipping the seat from red to blue.
Williams, who was already expected to face a competitive race for re-election, was handed worse odds after New York's congressional map was redrawn earlier this year.
New York's 22nd Congressional District lies in the central part of the Empire State and includes the cities of Syracuse and Utica.
It was also one of 16 districts won by House Republicans in 2022 after President Biden won the White House race in 2020.
Williams won the seat in 2022 after former Rep. John Katko, R-N.Y., who voted to impeach Trump, retired.
The seat was formerly occupied by ex-Rep. John Katko, R-N.Y., who voted to impeach Trump. (Tom Williams/CQ-Roll Call, Inc via Getty Images)
The Navy officer-turned-truffle farmer ran his campaign as a traditional conservative and endorsed Trump in January.
Mannion is a former teacher who had the endorsement of New York state's teachers union.
Both candidates have been accused of acting aggressively toward aides, however.
An open anonymous letter signed only by "Concerned Mannion Staff" said his New York state Senate office was a toxic work environment "including mistreatment, harassment, and retaliation." Mannion told local outlet CNY that the accusations were a "false political attack."
Trump and Williams have backed each other. (Anna Moneymaker/Getty Images)
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A subsequent investigation commissioned by the state Senate cleared Mannion.
Meanwhile, a video captured of Williams at a holiday event in late 2023 showed him telling his former chief of staff, "You f--- with my family, I’ll end every relationship that you have."
Williams told Politico at the time the confrontation occurred because the ex-staffer allegedly tried to blackmail Williams using his daughter's OnlyFans account.
Elizabeth Elkind is a politics reporter for Fox News Digital leading coverage of the House of Representatives. Previous digital bylines seen at Daily Mail and CBS News.
Follow on Twitter at @liz_elkind and send tips to elizabeth.elkind@fox.com