Luke Bronin, the former mayor of Hartford who campaigned on the need for new voices in Congress, soundly defeated long-time incumbent U.S. Rep. John Larson in the Democratic primary on Tuesday, all but guaranteeing Bronin the seat.

The Associated Press called the race around 10 p.m. on Tuesday with Bronin besting the congressman, 53.5% to 34.7%, with an estimated 51% of votes counted.

The other candidates, Jillian Gilchrest and Ruth Fortune, combined for about 11.8% of the votes at 10 p.m., according to AP.

The healthy margin of victory suggested that Bronin’s primary message — that Democratic voters want a change in leadership — resonated in the district. In his victory speech, Bronin referred to it as a “political earthquake in Connecticut.”

Larson, the 78-year-old congressman who was in the fight of his political life, is the latest Democratic incumbent to lose a primary as younger candidates around the country launch intra-party bids in an effort to reorient the party and reshape Congress. After serving 28 years in Congress, he fell short of the Democratic nomination for a 15th term.

Bronin, his most well-financed challenger who upset him at the nominating convention for the party’s endorsement, premised his campaign around the need for generational change and newer candidates who can take on President Donald Trump, especially if Democrats can retake the majority in the U.S. House in November.

Bronin, 47, served as the mayor of Hartford for two terms, leaving office in 2024.

Tuesday’s primary tested whether voters want experience and seniority in Congress or a fresh face to bring a new energy as incumbent lawmakers faced challenges in primaries across the country. Before Tuesday, half a dozen Democratic incumbents in Congress lost primaries that turned on ideological and generational issues.

Larson entered his election night watch party at Connecticut River Academy in his native East Hartford shortly before the race was called for Bronin. He was quickly swarmed by dozens of his supporters who gave him thunderous applause and cheered “JBL.”

As attendees circled around him, Larson decided to speak in the middle of the room instead of going to the podium. He gave a heartfelt speech thanking the other four Democrats in Connecticut’s congressional delegation who supported him, including U.S. Rep. Joe Courtney, D-2nd District, who attended the party.

“In some respects, I feel apologetic that I let them down,” Larson said about his colleagues, as the crowd shouted, “No you didn’t.”

“At the beginning of this debate, people said, well, now is when you find out who your friends really are,” he continued. “Nothing truer could have been said. When I look around this room this evening, now’s when you know who your friends really are.”

Larson specifically gave Fortune and Gilchrest a shoutout as “incredible candidates.” But in his 10-minute speech to supporters, he didn’t mention Bronin by name.

He said after his speech that he spoke with Bronin and congratulated him.

“The people of this district have spoken, and it’s time for us to come together and make sure that we all join forces,” Larson said to an emotional crowd as he was surrounded by his fmaily. “Because the issue here as I said throughout this campaign is Donald Trump and what he’s doing to this country.”

When asked by reporters whether he would seek the Working Families Party line or mount an independent bid in the fall, he quickly brushed aside those questions by saying, “take the night off, relax, take a deep breath.” He went back to mingling with supporters. But he indicated in his speech that he’s focused on the remaining months of his term to take on Trump.

“There’s still a lot of fight left and a lot to be done,” Larson said. “And I intend to fulfill my responsibility until the last day.”

At his election night party in Hartford, Bronin’s relative youth was underscored by his 17-year-old daughter introducing him after Larson’s concession. Luna Bronin, the oldest of his three children, spoke about her father as an inspiration and the person who can stand up to Trump.

“He believes in fighting for a world that he would be proud to hand to my generation,” Luna Bronin said.

Her father took the stage with his children and campaign staff behind him. 

“This is a political earthquake in Connecticut,” Bronin said. “The goal is to shake things up in Washington D.C., and we’re just getting started.”

Hartford Mayor Arunan Arulampalam and State Treasurer Erick Russell were among attendees at Tuesday night’s party at J Under the Dome in Hartford. The bar was crowded, and spirits were high with supporters who cheered as voting results showed their candidate gaining a stronger lead through the evening.

Bronin thanked the three others who ran in the primary for their service, starting with Larson, saying the congressman had given a “lifetime of service.” Bronin spoke about the need for sensible artificial intelligence regulation, better affordability and more renewable energy. He also said he wants to see a national Democratic party that embraces young people as an active part of the political process.

“I think there are so many young Americans who have given up on our politics, who have lost faith that our system is capable of making changes that matter to them, and we built a campaign where young people were very much a part of it,” Bronin said.

The four-way primary for the 1st Congressional District, which is centered around Hartford, was unprecedented. Larson won an open House seat in 1998 and hadn’t faced a primary challenge since.

Because Connecticut rarely sees primaries, it garnered attention that started to break through nationally as super PACs got involved in the final weeks. Outside groups poured in more than $2.5 million into the race on behalf of Bronin and Larson, with the former mayor getting a much bigger boost in spending. The congressman was ultimately outspent.

The outcome of the race won’t have any bearing on which party controls Congress next year since it’s a safe Democratic seat in a blue state. But it’s part of a national trend of younger candidates taking on longtime members as voters channel frustration at a Democratic Party that has little leverage in Congress in the minority.

Calls for generational change from Democrats got louder following catastrophic losses in the 2024 elections.

Unlike other House primaries in New York and Colorado or even Connecticut’s gubernatorial primary, the race for the 1st District wasn’t run as much on ideological grounds from Bronin and the other challengers but more on the push for new — and younger — leaders in Congress.

Those themes were reflected in a deluge of TV ads, mailers and text messages from the Bronin and Larson campaigns and the outside groups supporting them.

Gilchrest and Fortune struggled to break through in the same ways, especially because they weren’t able to compete financially as the bulk of major donations and spending by outside groups flocked to Bronin and Larson. The two women bemoaned the heavy emphasis on spending in the race and the donations that went to Bronin and Larson from billionaires and wealthy networks.

Gilchrest, a state representative from West Hartford, narrowly qualified for the August primary after some of Larson’s delegates flipped to support her at the nominating convention. Like she did in her first race in 2018 for state representative, she spent a lot of time canvassing in her campaign for Congress. Gilchrest relied on that strategy without the same funds as Bronin and Larson.

“I think it says that there’s an overall frustration with how our federal government is not working right now. And voters are sick and tired of politicians saying one thing and then not taking action,” Gilchrest said in the days before the primary. “And so I think that this primary really illustrated that voters want people who have new ideas and who want to push for actual change because this country is not functioning right now.”

Fortune, an estate attorney who was a first-time candidate for office, didn’t secure a spot on the primary ballot through the conventional route of the nominating convention. But she overcame the logistical challenge of qualifying for the primary by securing thousands of signatures through petition signatures.

“The journey has been worthwhile,” Fortune said on the final weekend before the primary. “I’ve gotten to know the other candidates and I can tell you, I disagree with each of them in some key areas, but I do think they are brave and decent human beings. No one chooses to do this for vanity in my view. You must be driven by something somewhat bigger than you or purpose to want to do this.”

Bronin is now the heavy favorite in November’s general election. Of the five U.S. House seats in Connecticut, the 1st District is the bluest.

Dr. Amy Chai, the GOP nominee in the 1st District, spent Tuesday out at the polls, telling voters about her campaign. She said she’s heard from Democrats who aren’t happy with their choices. She was previously an independent but “realized she couldn’t win” unless she was affiliated with a major party.

“My motto is listen more, hate less,” Chai said. If elected, she wants to focus on the prevention of mental illness and addiction. She believes politics is making mental health disorders worse.

The 1st District primary was the only one for Democrats on the federal side. Republicans, meanwhile, held two primaries in the 4th District and the 5th District. But Democrats are strongly favored, especially since the party in power historically faces headwinds in a midterm election.

Michael Goldstein, a doctor and attorney, defeated Dan Miressi, a youth hockey coach, in the 4th Congressional District, which is situated in the southwestern corner. Goldstein will face U.S. Rep. Jim Himes, who is favored to win a 10th term in Congress.

The 5th District remains the most competitive in the state. Chris Shea, a firefighter and retired Navy SEAL, bested Jonathan De Barros, who works as a mentor for at-risk youth, for the GOP nomination in the sprawling Northwestern Connecticut district.