New York (AP) — The Kennedy dynasty won't be returning to Congress next year.

Kennedy family scion and political novice Jack Schlossberg lost Tuesday to New York state Assembly Member Micah Lasher, in a closely watched and crowded Democratic primary for an open congressional seat in the heart of Manhattan.

READ MORE: Mamdani slate sweeps Democratic primaries in New York, ousts 2 incumbents from Congress

Lasher has spent his career in politics, working for officeholders including the man whose seat he hopes to win in November, Democratic longtime Rep. Jerry Nadler. Flanked by another former boss, Gov. Kathy Hochul, and other politicians in New York City's Democratic establishment, Lasher said in his victory speech that he aimed to "revamp and recharge the Democratic Party in Washington" and to show it has "bold new ideas to improve the lives of struggling Americans and then deliver on them."

Lasher is well positioned for November's general election — Democrats make up two-thirds of the district's registered voters.

Before the race was called, Schlossberg had made an early appearance at his evening watch party at a Manhattan concert venue to thank his campaign workers and reiterate his message that Democrats need to put forward more frank, responsive and inspiring candidates "who are willing to speak plainly about the cost of living, about corruption and fearlessly about the Constitution."

"We don't just need younger candidates. We need different people," he said, adding, "unless Democrats learn from the signals that are being sent all across the country, we are going to keep on losing."

About an hour later, deflated "oohs" rippled through the room of largely young supporters as they got news of Lasher's victory.

The campaign was colorful and hotly contested, partly because of Schlossberg's star power as the social-media-savvy grandson of the late President John F. Kennedy, but also because the race became an expensive proxy fight among artificial intelligence interests.

Schlossberg got plenty of attention in the race, as a member of a famous political family who delivered his own "progressive and aggressive" message in dynamic and popular, if sometimes wacky, social media posts.

Supporters "don't just like me because I'm a Kennedy," Schlossberg told The Associated Press earlier this year. "They like me because of my experience, my ideas, and they trust me because they see what's going on with their very own eyes."

But he also faced questions about his limited professional resume and his seriousness as a candidate. The 33-year-old, who holds a joint law and business degree, worked briefly at the State Department's environmental bureau and has written political opinion pieces for Vogue. He said that family money bought him independence from political fundraising.

Money cascaded into the race as some tech and AI companies lined up against candidate Alex Bores, a former tech company engineer and a state Assembly member who wrote legislation that many in the industry opposed. But some other, more regulation-friendly AI heavyweights counterpunched by trying to help Bores.

READ MORE: JFK's grandson Jack Schlossberg will run for U.S. House seat in New York

Voters in the district were deluged with mailers and ads, particularly about Bores and rival Micah Lasher, a fellow Assembly member and former Nadler aide. Lasher emphasized his long experience working in government for Nadler and others. Bores positioned himself as a fresher face who stood up to powerful interests.

"I didn't get in this race to make a point about AI, but some of the most powerful people on the planet, a handful of oligarchs hell-bent on preventing any regulation of their industry whatsoever … decided they wanted to make an example out of this race. This was a huge and unprecedented fight, and we did not back down," Bores said in a concession speech.

Alongside the AI battle, the race featured competing endorsements from Nadler and Carolyn Maloney, the fellow Congress member whom he defeated in a 2022 primary after their once-neighboring districts were largely combined by redrawn maps. This year, Maloney endorsed Bores, while Nadler endorsed Lasher.

Candidate George Conway had his own political connections, though not necessarily ones he embraced — a former Republican, he was married to Kellyanne Conway, a former adviser to Republican President Donald Trump before distancing himself from both of them. A veteran attorney, George Conway helped create the anti-Trump organization called The Lincoln Project.

Trump reveled in Conway's defeat, calling him "a Trump Deranged Loser" in a social media post.

Several other candidates also vied for the nomination.

Associated Press journalist Emily Wang Fujiyama contributed.