Representative Jerry Nadler, the chairman of the House Judiciary Committee, handily beat fellow Democratic Representative Carolyn Maloney in the primary for New York's 12th District.
Mr Nadler, who as chairman of the House Judiciary Committee led the the first impeachment of former president Donald Trump, beat Ms Maloney, who serves as chairwoman of the House Oversight & Government Reform Committee.
New York's state legislature initially proposed a gerrymandered map that would have helped Democrats. But the state's Supreme Court tossed out the map, which forced Mr Nadler, who represents parts of the Upper West Side, against Ms Maloney, who represents the Upper East Side of New York City.
Mr Nadler had criticised Ms Maloney for her vote for the Iraq War, the Patriot Act and her opposition to the United States's nuclear agreement with Iran during one debate, according to ABC7. Mr Nadler was on the other side of each issue.
Ms Maloney, for her part, argued that it was important to have a woman's voice in Congress as abortion rights are under assault after the US Supreme Court handed down Dobbs v Jackson, which overturned Roe v Wade.
Ms Maloney, for her part, was forced to apologise when she said that President Joe Biden would not run for re-election in 2024, only to tell The New York Times editorial board that Mr Biden would not run again. She prefaced the comment by saying it was off the record.
In addition, Ms Maloney received intense criticism for her past vaccine skepticism and proposed legislation that would study a link between vaccines and autism. For her part, Ms Maloney pushed back on accusations that she was an anti-vaccine, saying simply, "I regret asking to study vaccines."
Mr Nadler's win is considered a victory for progressives as the Working Families Party backed Mr Nadler. Mr Nadler also beat young upstart Suraj Patel.
Mr Trump, a frequent target of both incumbents, attempted to insert himself into the primary, posting a cheeky endorsement of Ms Maloney on Truth Social, calling her "a kind and wonderful person, who has always said terrific things about me." This came despite the fact she was acting chairwoman of the Oversight Committee during his first impeachment inquiry.
Ms Maloney, for her part, rejected the endorsement.
"He should be more concerned about the investigation I'm leading as Chair of the Oversight Committee into the storage of his classified documents at Mar-a-Lago," she said.
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