New York City Mayor Zohran Mamdani’s endorsements in three House races could boost the standing of the political left in the halls of Congress if his preferred candidates win their primaries later this month.

Mamdani’s win in last year’s mayoral race was a landmark victory for the left, as Mamdani is a member of the Democratic Socialists of America (DSA). Progressives are hoping to expand on that progress in the midterms in November, and these three congressional races present perhaps their best opportunities to elect more left-leaning members into the House.

The races are also a key test of Mamdani’s political capital roughly six months after he entered office in January. Victory for his candidates would indicate he is increasingly influential in New York politics—but losses for those candidates would be a warning sign for his popularity among New York voters.

The trio of races will be Mamdani’s “biggest test since his own election in November,” Joseph Viteritti, the Thomas Hunter professor of public policy at Hunter College, told Newsweek on Friday.

“It will measure not just the strength of his endorsement, but of his overall message, which already seems to be resonating beyond New York and across the country,” he said.

Newsweek reached out to Mamdani’s office for comment via email.

Can Mamdani Become New York City Kingmaker? What Polls Show

Mamdani has endorsed candidates in three competitive primaries ahead of the June 23 primary. He endorsed in one open race, as well as two challengers running against incumbent Democratic members of Congress.

He endorsed Assemblymember Claire Valdez over Brooklyn Borough President Antonio Reynoso in District 7, former City Comptroller Brad Lander over Representative Dan Goldman in District 10 and organizer Darializa Avila Chevalier over Representative Adriano Espaillat in District 13.

Here is a look at where each of those races stand.

Valdez vs. Reynoso: New York’s 7th District

Polling suggests Valdez is in a close race against Reynoso, but that many voters remain unsure of who they will support in this Democratic primary. They are running to succeed Representative Nydia Velázquez, who has served in Congress since 1993 and is not seeking reelection.

Valdez, a DSA member, is a relative newcomer to New York City politics, having been first elected to the State Assembly in 2024. Prior to serving as borough president, Reynoso served on the city council in 2014.

An Emerson College poll showed Valdez with 23 percent support, compared to Reynoso’s 21 percent. City Councilmember Julie Won had 13 percent, while activist Vichal Kumar had 1 percent. Many voters—43 percent—were still undecided. The poll surveyed 350 likely voters from May 16-17.

An earlier Data for Progress survey showed Reynoso with a lead. He had support from 28 percent of respondents compared to Valdez’s 24 percent. Forty-six percent of respondents were undecided. It surveyed 366 likely voters from January 15-19.

The district is viewed as among the most progressive in the country and contains parts of the city's "Commie Corridor."

Lander vs. Goldman: New York’s 10th District

Lander, the former New York City comptroller who ran for mayor in the 2025 election, has received Mamdani’s support for taking on Goldman.

It's rare for incumbents to lose renomination, but some on the left believe Goldman is a poor fit for the progressive district Mamdani won in last year's mayoral race over former Democrat Governor Andrew Cuomo. Goldman is not viewed as particularly progressive and has drawn scrutiny from some on the left over his support for Israel.

An Emerson College poll found that 57 percent of respondents planned to vote for Lander, compared to Goldman’s 23 percent. It surveyed 450 likely voters from May 16-17 and had a margin of error of plus or minus 4.6 percentage points.

An earlier Schoen Cooperman Research Poll, which surveyed 465 likely voters from May 1-4, showed a tighter race but still gave Lander an advantage. In that poll, 47 percent of respondents said they would back Lander compared to 42 percent for Goldman. It was first reported by City & State.

Mamdani has supported Lander's campaign from the beginning, telling The New York Times in December, "He has been a trusted ally and partner of mine, and I'm proud to support him as I know he'll continue delivering for those who need government to show up for them the most."

The pair became allies on the mayoral campaign trail last year, with both occupying the more progressive lane in the race. Lander ultimately encouraged his supporters to rank Mamdani second in the primary election, as the city uses ranked choice voting in its mayoral elections.

The district contains parts of Brooklyn and Manhattan.

The Lander campaign told Newsweek he is “proud” to have the support of Mamdani but is “taking nothing for granted and continuing to run like we’re in the fight of our lives.”

“We’ve got a fascist in the White House, rogue ICE agents in our streets, and billionaires trying to buy our elections. But Brad knows that neighbors showing up for each other is how we fight back. He's going to keep relentlessly organizing alongside them, through the primary on June 23rd, and far beyond,” the statement said.

Avila Chevalier vs. Espaillat: New York’s 13th District

Mamdani’s endorsement of Avila Chevalier puts him at odds with other national progressives who have endorsed Espaillat, who has represented the district, based in Upper Manhattan and parts of the Bronx, since 2017.

A Data for Progress poll, reported by Semafor, gave Avila Chevalier a lead with 39 percent to Espaillat’s 35 percent. It surveyed 319 likely primary voters from June 3-9.

An earlier Upswing Research & Strategy poll, reported by the City Reporter, gave the incumbent a lead over Avila Chevalier. In that poll, 42 percent said they would vote for Espaillat, while 28 percent said they would cast a ballot for Avila Chevalier. It surveyed 598 likely voters from March 25-30.

How Popular Is Zohran Mamdani?

Polls suggest Mamdani is popular with a plurality of New Yorkers, but some are still skeptical of his tenure.

A Marist University poll, which surveyed 1,454 adults from March 26-31, showed that 48 percent of New Yorkers approve of Mamdani, while 30 percent disapprove. It had a margin of error of plus or minus 3.3 percentage points.

Meanwhile, an Emerson poll found that his approval stood at 43 percent, while his disapproval stood at 27 percent. It surveyed 850 registered voters from April 5-6 and had a margin of error of plus or minus 3.4 percentage points.

Earlier this year, Mamdani endorsed Lindsey Boylan—a member of the DSA and the first woman to publicly accuse Cuomo of sexual harassment, which he has denied—in a special election for a city council seat. However, she lost to fellow Democrat Carl Wilson in April.

Mamdani drew ire for endorsing Boylan over Wilson, who is gay, in a district with a large LGBTQ+ population and several sites important to the community.

Mamdani did not endorse a primary challenge from City Councilmember Chi Ossé against House Minority Leader Hakeem Jeffries. Ossé ended his campaign last month.