Bucking Democratic leaders, Mamdani endorsed Brad Lander, Claire Valdez, and Darializa Avila Chevalier in three competitive House primaries in New York City. All three candidates’ campaigns were characterized by progressive economic policies and criticisms of U.S. military and financial support for Israel, which they accused of committing “genocide” in Gaza. The three Democratic nominees are expected to win in the general election in the fall.

Two of Mamdani’s endorsees—Lander and Avila Chevalier—unseated Democratic incumbents, including the powerful chair of the Congressional Hispanic Caucus.

Brad Lander

Former New York City Comptroller Brad Lander won two-thirds of the vote in the Democratic primary for New York’s 10th District, defeating two-term Democratic Rep. Dan Goldman. Lander, 56, ran on a progressive platform focused on affordability.

“It was an honor one year ago to work together to elect him the mayor of New York City,” said Lander, who initially ran for mayor alongside Mamdani and cross-endorsed Mamdani’s campaign for the ranked-choice mayoral primary, in his victory speech. “What a glorious time to be a New Yorker.”

Lander called out U.S. support for Israel in his victory speech and suggested that it’s become a losing strategy for the Democratic party.

“Our party needs to admit that Joe Biden’s ‘hug Bibi’ strategy was a catastrophic mistake. I believe it made us complicit in genocide,” he said. Lander, who is Jewish, has long been involved in progressive activism with Jewish organizations and highlighted the differences in his views on Israel from Goldman, who is also Jewish. He previously criticized Goldman for accepting donations to his campaign from the largest pro-Israel lobbying group AIPAC and for not supporting legislation to block further U.S. military aid to Israel. Goldman has been a vocal advocate against anti-Semitism, including from within his own party.

“As history has taught us: Antisemitic tropes and stereotypes, some of which I heard personally on this campaign, will ultimately be the undoing of our democracy if we all don’t lean in and speak out, even if it’s not politically expedient,” Goldman said in his concession speech. “The Democratic Party has always been at its strongest when it has welcomed a broad coalition of voices, united by those shared democratic values of equal rights, social justice, human rights.”

Claire Valdez

State legislator Claire Valdez won in an open race for New York’s 7th District against Brooklyn Borough President Antonio Reynoso. Rep. Nydia Velázquez, who is retiring from the district, and the Working Families Party had endorsed Reynoso.

Valdez is serving her first term in the state Assembly. The 36-year-old, who moved to New York City in 2015, ran a campaign centered on “Medicare for All,” public housing, and labor issues, and was vocal in her criticism of Israel and advocacy for Palestinians. She was endorsed by several pro-Palestinian groups. She is a member of the Democratic Socialists of America (DSA).

“We haven’t just won an election, we have declared that this movement is durable,” Valdez said in her victory speech. “It will not stop until working people are no longer asked to just build the table, no longer just offered a seat at the table, but will run the table.”

Darializa Avila Chevalier

Darializa Avila Chevalier, a 32-year-old community organizer, narrowly won New York’s 13th District against five-term incumbent Adriano Espaillat.

Avila Chevalier, a democratic socialist, had the backing of progressive groups including the NYC-DSA and Justice Democrats, but Mamdani’s endorsement and active campaigning alongside her boosted her visibility. She campaigned on affordable housing, immigrant rights, and expanding the social safety net.

Espaillat, also the chairman of the Congressional Hispanic Caucus, had the backing of top Democrats, including House Minority Leader Hakeem Jeffries. The 71-year-old was the first Dominican-American to be elected to Congress and his campaign emphasized his advocacy against President Donald Trump’s anti-immigration agenda.

“Tonight wasn’t our night, but I love you anyway,” Espaillat said in his concession speech to supporters. Espaillat, who immigrated to the U.S. from the Dominican Republic in 1964, said it was the “privilege of my life to serve you, the community, and I will continue to love and serve this community the best way that I can.”

When asked if he had a message for Mamdani, whom Espaillat had endorsed in the mayoral election, he said, “I respect the mayor’s decision.”

Speaking to Avila Chevalier’s supporters after her victory, Mamdani said, “I was asked time and again, why would I support this campaign? And I said then, I can think of no better person than the daughter of a single mother caseworker who has fought for working people her entire life, who has stood up for New Yorkers unjustly detained by I.C.E., who has called for a foreign policy of investing in babies and not bombs.”

Avila Chevalier cast Espaillat as out of step with constituents on issues like economic inequality and Israel’s war in Gaza, while Espaillat criticized Avila Chevalier for past social media posts in which she called for the abolition of police and criticized Democratic leaders, including a since-deleted post from 2021 that said, “F-ck Kamala Harris.” (Avila Chevalier has since apologized to Harris.) Avila Chevalier also faced racist attacks and false accusations about her ethnicity from a senior advisor to Espaillat, which Mamdani condemned and Espaillat’s campaign disavowed.

“Every one of us has a story about being let down by our governments, about our representatives … who wouldn’t pick up the phone, doing nothing about the affordability crisis,” Avila Chevalier said in her victory speech. “That ends today.”

Party priorities

Attention is also turning to upcoming Democratic Senate primaries in Michigan and Minnesota, where progressive candidates Abdul El-Sayed and Peggy Flanagan, the state’s lieutenant governor, are among the frontrunners in each race.

The DSA has a higher net favorability among Democratic voters than Democrats in Congress by 13 points, according to a poll highlighted by CNN, while Gallup polling from September found that 66% of Democrats—up from 50% in 2010—view socialism more positively than capitalism.

Republicans have already seized on the apparent shift. Tuesday “was the night the Democrat establishment officially surrendered to Zohran Mamdani and the socialist wing of their party. Every House Democrat, in safe and competitive districts alike, will now answer to the radicals calling the shots. And Americans should be terrified by where the Democrat Party is headed,” National Republican Congressional Committee spokesperson Mike Marinella said in a statement.

Some Democrats are also unhappy about the insurgent trend within the party. “I say this with no ill will or animosity: if you hate the Democratic Party, then please don’t run for our nomination,” former Democratic National Committee chair Jaime Harrison posted on X.

But others saw the progressive victories as an indication from the public of growing dissatisfaction with the status quo and a desire for more ambitious reforms.

“Who is ‘the Democratic Party’ if it’s not the voters?” posted Sen. Chris Murphy (D, Conn.). “Democratic voters choose candidates, not party leaders. And party leaders need to listen to what voters are telling us - and right now they are demanding our party be bolder.”

Tuesday’s primaries, which took place across four states, also saw some key contests in which super PACs funded by the artificial intelligence industry spent heavily. 

In another New York race, Democrat Alex Bores, who became a national figurehead for advocating AI-safety regulation, lost a closely watched primary to represent Manhattan’s 12th Congressional District—a contest that was viewed by some political observers as an early test of whether concerns about artificial intelligence would resonate with voters. 

Still, Bores hailed the awareness his campaign brought, telling POLITICO, “We came within a whisker of winning it…Getting the message across is far more important than whoever the one person is who represents this district.” In his victory speech, fellow Assemblymember Micah Lasher, also warned the AI companies that took “such an unusual interest” in the race, with some spending millions of dollars to oppose Bores and others to support him, “I won’t be taking my cues from either of you when it comes to protecting our kids, our jobs and our families.”