In an unpleasant end to a bitter New York Democratic primary on Tuesday, allies of two powerful House committee chairs traded nasty barbs – before one saw a long career in Congress brought to an untimely end.

Carolyn Maloney, chair of the House oversight committee, said her opponent in New York’s 12th district, Jerrold Nadler, was “half-dead”, possibly senile and unlikely to finish his next term in Washington, CNN reported. Allies of Nadler, the judiciary chair, called Maloney “kooky” and “not entirely sober”.

In the end, Nadler’s political career remained wholly alive. With nearly 90% of results in when the race was called, he had taken 56% of the vote to 24% for Maloney. A third candidate, Suraj Patel, brought up the rear.

Speaking before the vote, Nadler told CNN: “It’s obviously not true that I’m half-dead, it’s obviously not true that I’m senile … Let them flail away.”

In his victory speech, Nadler said he and Maloney “have spent much of our adult lives working together to better both New York and our nation. I speak for everyone in this room tonight when I thank her for her decades of service to our city.”

Nadler and Maloney, both septuagenarians with 30-year Washington careers, were forced into their undignified fight to stay in Congress by redistricting, after the New York supreme court said Democrats gerrymandered the map.

Nadler, 75, was first elected in 1992. As chair of the House judiciary committee, he led both impeachments of Donald Trump. He was buoyed in the last weeks of the primary campaign by endorsements from the New York Times and Chuck Schumer, the Senate majority leader.

He said he would go back to Congress “with a mandate to fight for the causes so many of us know to be right”, including abortion access and climate change.

Maloney, 76, also first elected in 1992, is the first woman to chair the House oversight committee. Known for her advocacy for 9/11 first responders seeking compensation for diseases they attribute to contamination from the destruction of the World Trade Center, she once wore a firefighter’s jacket on Capitol Hill and at the 2019 Met Gala.

On Tuesday, Maloney said women in politics still face misogyny, something she said she experienced herself in her primary campaign.

“I’m really saddened that we no longer have a woman representing Manhattan in Congress,” Maloney said. “It has been a great, great honor and a joy and a privilege to work for you.”

Among other New York Democratic contests teed up by district changes, Sean Patrick Maloney, a senior party figure, saw off Alessandra Biaggi, a progressive backed by the congresswoman Alexandria Ocasio-Cortez, by a comfortable margin, 67% to 33% at the point the race was called.

Elsewhere, Daniel Goldman, lead counsel in Donald Trump’s first impeachment trial, beat Mondaire Jones, one of the first two gay Black men in Congress, and Yuh-Line Niou, another progressive candidate, in a tightly fought race.

In the Republican primaries, Carl Paladino – a far-right former candidate for governor who has praised Hitler, made racist remarks about Barack and Michelle Obama and said the US attorney general, Merrick Garland, should be executed – established an early lead over his opponent in a Buffalo-area seat before being reeled in and defeated by Nick Langworthy, chair of the state party.

There was also a key special election for Congress, in which Pat Ryan, the Democrat, established an early lead over Marc Molinaro, his Republican challenger in the 19th district. Molinaro made up ground as the night went on – before the race was called for Ryan, 51% to 49%.

Ryan will only sit in Congress until the end of the year, as both men will fight other seats in November. But observers were watching closely for clues as to voter intentions less than three months before the midterms.

Republicans are favoured to retake the House, as opposition parties often do in the first midterms of a presidential term. But the win for Ryan will be seized upon by national Democratic leaders hoping that recent domestic legislative successes and the excesses of the conservative-dominated supreme court, particularly on abortion, could tilt the midterms contests their way.

The New York seat fell vacant when Antonio Delgado, a Democrat, resigned from Congress to become lieutenant governor to Kathy Hochul. Republicans targeted the district as a possible flip, with heavy campaign spending.