Mamdani, Sanders-endorsed Candidates Win Big on Election Night

Progressives cast primary victories as a referendum on the future of the Democratic Party

By Audrey Hill

Still clad in a Knicks jersey from the championship parade earlier in the day, Mayor Zohran Mamdani told a roaring crowd in Brooklyn’s Kings Theater on June 18 that his election the previous November was just the beginning.

“I see New Yorkers going to work every hour and still finding time to dream in that same hour, that tomorrow could be more than today,” told a crowd of hundreds. “If anyone can sustain this movement, if anyone can win these elections, if anyone can shock this country, it is you. You have done it before and on Tuesday, we will do it again.”

The rally, organized by the Democratic Socialists of America (DSA) and headlined by Mamdani and longtime progressive champion Sen. Bernie Sanders, was designed to give a slate of candidates endorsed by the pair a late boost in the days before New York’s primary election. But more than that, it was a push to enfold the momentum engendered by Mamdani’s mayoral victory into the wider working-class progressive movement and launch progressive allies in New York into positions in Congress and the State Assembly.

“If we want to build a movement that wins, we need leaders across our city who are willing to fight with everything they have for working people,” Mamdani told the crowd.

The rally included congressional candidates Brad Lander in New York’s 10th Congressional District, Claire Valdez in the 7th, and Darializa Avila Chevalier in the 13th, all of whom won their elections at the end of June, with Lander and Chevalier unseating incumbent candidates. Also featured were five assembly candidates (who also emerged victorious on election night) including Ilapa Sairitupac for Assembly District 65 in Lower Manhattan and Eli Northrup in Assembly District 69 in Upper Manhattan.

While the specific contours of each race are not quite so easily flattened, speakers generally tried to paint the races as a choice between an establishment of the past and a progressive politics of the future. Issues touched upon included affordability, immigration, and U.S. involvement in foreign wars, and frequently cast the Democratic Party establishment as corporate, complacent, and unwilling to present a positive vision for the future.

“This is not the time for strongly worded letters, or high dollar fundraisers, or elections bought by billionaires, crypto bros, or AI oligarchs,” NY-10 candidate Brad Lander said. “It’s time for a politics of solidarity.”

Lander, a stalwart progressive figure in New York politics rose to citywide prominence during the 2025 mayoral race, in which he finished third after cross-endorsing with Mamdani. The mayor was one of the first to endorse Lander’s candidacy against two-term incumbent Dan Goldman in New York’s 10th Congressional District, which includes Lower Manhattan and parts of Brooklyn.

“We ran this campaign like a team sport, because that’s what it takes to stand up to billionaires and bullies,” Lander told supporters in his victory speech on election night. “And that’s what I intend to do in Congress. Our team of progressive champions has been winning across the country, and our ranks will keep growing, tonight and in the months ahead.”

While he has a fairly progressive voting record on some issues, Goldman’s support for Israel, unwillingness to eschew corporate PACS, and use of his personal wealth to support his campaign emerged as key issues in the race — and seem to have ultimately decided his fate.

The importance of solidarity and approaching politics like a team sport was often echoed on the campaign trail by both Assembly Member Claire Valdez, who will fill the seat of outgoing Rep. Nydia Velasquez, and Darializa Avila Chevalier, who unseated incumbent Rep. Adriano Espaillat. Both frequently emphasized rent burdened districts, the outsized influence of special interests, and money going to foreign wars that could instead be spent on the most vulnerable at home.

One of the few establishment victories for the night was in New York’s 12th Congressional District, which spans the Upper West and Upper East sides, where West Side Assembly Member Micah Lasher triumphed over East Side Assembly Member Alex Bores, Kennedy scion Jack Schlossberg and public health advocate Nina Schwalbe. Both Sanders and Mamdani declined to weigh in on the hotly contested race.

As much as those on the left sought to project unity, the slate also revealed some of the movement’s internal fissures. Sanders has not endorsed Avila Chevalier, though she was backed by Mamdani. Valdez’s race in the 7th Congressional District has put Sanders, Mamdani and the DSA at odds with the Working Families Party and a number of unions, who backed organizer and Brooklyn Borough President Antonio Reynoso. In recent years, Lander has also put distance between himself and the DSA label. Still, those differences were largely absent from the stage in the final days of the primary, where the emphasis remained on solidarity, affordability, and a shared hope in a progressive movement.

As he closed out the rally, Sanders hypothesized that the progressive movement, which has been gaining traction in races across the country, is surging because the American people are finally waking up to the corruption of the system and the need for candidates who meet the moment. He said, “They have realized that the politics and the policies of the Democratic establishment are no longer good enough. In this dangerous, unprecedented moment in American history, tinkering around the edges just won’t work.”

Mamdani made it clear that he understood the implications of progressive victories in New York to extend, both geographically and symbolically, far beyond the confines of the city. “Now, people often ask me what I think of the state of the Democratic Party. This slate here today is our answer. The Democratic Party must change,” he said. “They tend to follow that question with another. Who do you want to run in 2028? Then they ask, ‘When does the race for 2028 begin?’ It starts now. It starts on Tuesday.”