Mamdani-Backed Progressives Win Democratic Primaries, Now Face the Test of Governing in Congress

In June, inside Brooklyn's historic Kings Theatre, New York City Mayor Zohran Mamdani stood before a packed house and rallied support for a slate of congressional candidates he hoped would extend his progressive momentum to Washington. The crowd answered with chants of "Abolish ICE," "Tax the rich" and "Free Palestine." Within days, all three of his endorsed candidates had won their Democratic primaries.

The winners were Claire Valdez, Brad Lander and Darializa Avila Chevalier. Lander, the former city comptroller, defeated Congressman Dan Goldman in a race defined by Israel. Avila Chevalier, a community organiser, unseated longtime Congressman Adriano Espaillat. Valdez, a state assemblymember and member of the Democratic Socialists of America, won the contest to succeed the retiring Congresswoman Nydia Velazquez. Both Valdez and Avila Chevalier also had the backing of the city's DSA chapter. Because their districts are heavily Democratic, the primaries were effectively the main event, and all three are expected to win on Tuesday. On the eve of the vote, the city was politically quiet, with canvassers harder to find than before the primaries.

Their platforms overlap on abolishing Immigration and Customs Enforcement, ending US military aid to Israel, and Medicare for All. Their paths differ. Lander spent years in city government, lost to Mamdani in the 2025 mayoral primary, and then backed him. His race against Goldman drew national attention in a district with one of the largest Jewish populations in the country. Lander calls Israel's campaign in Gaza genocide and its occupation of Palestinian territory apartheid, yet identifies as a Zionist and has long supported a two-state solution. Two weeks before the election, Israeli forces detained him in the occupied West Bank while he volunteered in the olive harvest, and Israeli authorities have since revoked his travel documents for a planned return. He said the story he brings home is not his detention but "the ethnic cleansing of Palestinians in the West Bank," which he said he saw with his own eyes.

Avila Chevalier's rise was also shaped by immigration and Palestinian rights, though her approach is more uncompromising. After interning at a youth organisation in Nablus in 2014, she returned to the US and became an advocate for Palestinian communities. Her "Babies Not Bombs" platform would redirect military spending, including aid to Israel, toward childcare and healthcare. She told Al Jazeera budgets should be seen as moral documents. Valdez came up through the labour movement as a union organiser. She backs the PRO Act, national rent control and a government-run healthcare system, and said at a polling site on the first day of early voting that public programmes have been under attack from the right.

The goals of abolishing ICE and ending aid to Israel are unlikely to be achieved without navigating competing interests in Congress and the White House. With the balance of power potentially shifting toward Democrats, the newcomers must pick priorities. Progressive strategist Nomiki Konst pointed to Mamdani's filling of 200,000 potholes after taking office as the model of an early, visible win, and urged the group to agree on a shared issue and use the start of a Democratic Congress to press it.

Lander offered two candidates: a ban on members of Congress trading individual stocks, which he said might restore a little trust, and restoring enhanced insurance subsidies that expired at the end of 2025, raising premiums for many who buy private plans. He suggested refusing to pass a budget without them, forcing Republicans to vote and Trump to respond. Avila Chevalier would start with Babies Not Bombs; Valdez wants to pass the PRO Act.

Alexandria Ocasio-Cortez offers a precedent. She beat longtime incumbent Joe Crowley in 2018 and has at times worked with Republicans. In 2025 she introduced a bill with Florida Republican Anna Paulina Luna to cap credit card interest at 10 percent, echoing a Bernie Sanders and Josh Hawley proposal. Konst said the question is whether Mamdani's candidates can turn ideology into results, which requires compromise.

Avila Chevalier is already under scrutiny. She called for Police Commissioner Jessica Tisch to resign after ICE shot a man in his car with his child in the backseat, and said police shoved her to the ground during the ensuing protests. Mamdani reportedly appointed Tisch on Governor Kathy Hochul's recommendation, and an Atlantic report suggested Hochul's endorsement hinged on it. Avila Chevalier says she will work with anyone, naming healthcare and a moratorium on data centres as possible bipartisan ground. After Tuesday, the test shifts from winning votes to choosing what to fight for first.