In June, New York City Mayor Zohran Mamdani stood before a packed house of voters, rallying support for a new wave of candidates hoping to build on his progressive momentum by winning seats in Congress.

Inside Brooklyn’s historic Kings Theatre, the crowd answered chants of “Abolish ICE”, “Tax the rich” and “Free Palestine” with roaring applause, leaving little if any room for doubt about what the audience wanted from its politicians.

Within days, all three congressional hopefuls endorsed by Mamdani– Claire Valdez, Brad Lander and Darializa Avila Chevalier – had won their Democratic primaries, becoming the party’s candidates in the midterm election.

Lander, the former New York City comptroller, defeated Congressman Dan Goldman in a race in which Israel was the defining issue.

Avila Chevalier, a community organiser, unseated longtime Congressman Adriano Espaillat. Valdez, a lawmaker in the New York State Assembly and member of Democratic Socialists of America (DSA), won the contest to succeed retiring Congresswoman Nydia Velazquez. Both Valdez and Avila Chevalier had the backing of New York City’s DSA chapter.

The candidates’ heavily Democratic districts mean they are likely to win congressional seats in Tuesday’s midterm elections. The June Democratic Party primaries effectively served as the main event for voters.

In the final hours before Tuesday’s midterm election, New York City – a place colloquially dubbed the city that never sleeps – is more politically sleepy, with canvassers a bit harder to find than they were in the final stretch before the primaries.

For the three progressive candidates, the past few months have been a test of how to turn bold campaign promises into policy they can actually deliver. The often slow minutiae of daily governance stand in stark contrast to buzzword-laden campaign slogans on the posters and signs galvanising their base of voters.

Unique paths to politics The three congressional candidates’ platforms overlap on issues like abolishing Immigration and Customs Enforcement (ICE), ending US military aid to Israel and establishing a public healthcare system dubbed Medicare for All. But their paths into progressive politics differ.

Lander spent years in the New York City government, most recently as comptroller overseeing the city’s finances. After losing to Mamdani in the 2025 Democratic mayoral primary, he backed Mamdani in the election.

But Lander’s congressional campaign against incumbent Goldman brought him national attention, with Israel and Palestine emerging as the defining issue in the race to lead a district with one of the largest Jewish populations in the United States.

Lander has described Israel’s military campaign in Gaza as genocide and its occupation of Palestinian territory as apartheid. He also identifies as a Zionist who embraces pro-Palestinian activism, arguing that the positions are not mutually exclusive. Lander has long supported a two-state solution.

“It’s straightforward that some approach to more shared safety for Israelis and Palestinians and for Jews and Muslims and everybody else here makes more sense,” Lander said. “I also want to be able to listen across those divides and have thoughtful policy debates.”Two weeks before Tuesday’s election, Israeli forces detained Lander in the occupied West Bank while he was volunteering to help with the olive harvest. Israeli authorities have since revoked his travel documents for a planned return visit.

“The main story I come home with is not the story of my detention or the revocation of my travel authorisation,” Lander said. “The main story that I come with is the ethnic cleansing of Palestinians in the West Bank, which I just saw with my own eyes.”Lander has also long called for ICE to be abolished, including during President Donald Trump’s first term in office.

Pro-Palestinian activism Avila Chevalier’s political rise was similarly shaped by immigration and Palestinian rights, though she has taken a more uncompromising approach.

After interning at a youth organisation in Nablus in the occupied West Bank in 2014, she returned to the US and became an advocate for Palestinian communities.

Her “Babies Not Bombs” platform calls for redirecting military spending, including aid to Israel, towards domestic priorities such as childcare and healthcare.

“It’s important for us to see our budgets as moral documents,” Avila Chevalier told Al Jazeera. “Our resources should be going towards the things that make our lives dignified and make our communities thrive – not towards war, not towards ICE or things that are harming our communities.”Valdez, meanwhile, came to progressive politics through the labour movement. A former union-organiser-turned-state-assemblymember, she supports stronger labour protections, including federal legislation such as the Protecting the Right to Organize (PRO) Act to make union organising easier.

Valdez also backs national rent control and a government-run healthcare system to provide wider healthcare access than the country’s private-sector insurance model.

“Public programmes and entitlements have been under attack by the right,” Valdez told Al Jazeera as she exited a polling location in her district on the first day of early voting. “I think not just clawing those back but really advancing a vision for what those things should be will be top priorities.”Abolishing ICE and ending military aid to Israel are lofty, ambitious goals, and neither is likely to be achieved without navigating competing interests in Congress and the White House. With the balance of congressional power potentially shifting towards Democrats in the midterms, the newcomers will have to decide which priorities to pursue first.

That means looking for more immediate wins comparable to Mamdani’s move to fill 200,000 potholes when he took office as mayor, according to progressive political strategist Nomiki Konst.

“[Get] on the same page about an issue that we all agree on and leverage that in the Democratic Congress because there’s no better time than the beginning,” Konst told Al Jazeera. For Lander, one such measure is banning members of Congress from trading individual stocks.

“Maybe that restores a little bit of trust,” Lander said. “People say that’s gross that members of Congress trade stocks. At least this new Congress is doing something, you know, to show me they’re not just all in it for themselves.”Lander also sees an opportunity to restore enhanced government subsidies that expired at the end of 2025, raising premiums for many people who buy their private-sector insurance plans individually.

“We can say we’re not going to pass a budget that doesn’t do that and force Republicans to vote one way or the other and see what Trump does,” Lander said.

For Avila Chevalier, an early priority would be her “Babies Not Bombs” agenda, redirecting funding towards domestic needs. Valdez wants to pass the PRO Act.

Alexandria Ocasio-Cortez sets a precedent The three would not be the first progressive New Yorkers to enter Congress promising major change.

Alexandria Ocasio-Cortez won her legislative seat in 2018 by defeating longtime incumbent Joe Crowley. Since then, she has occasionally worked with Republicans on shared priorities.

In 2025, Ocasio-Cortez introduced legislation with Republican Representative Anna Paulina Luna of Florida to cap credit card interest rates at 10 percent, echoing a proposal from Senator Bernie Sanders of Vermont and Republican Senator Josh Hawley of Missouri.

The question, Konst says, is whether Mamdani’s endorsed candidates can turn ideological commitments into legislative results. Doing so will require compromise, including setting aside some priorities to advance others.

Avila Chevalier is under the microscope after calling for New York City Police Commissioner Jessica Tisch to resign over a man being shot in his car by ICE while his child was in the backseat. Avila Chevalier said she was later shoved to the ground by New York City police officers during protests following the shooting.

Mamdani reportedly appointed Tisch on the recommendation of Governor Kathy Hochul, whose support was important to Mamdani’s mayoral campaign. An Atlantic magazine report suggested that her endorsement of Mamdani, whose more progressive platform included universal childcare and government-operated grocery stores, hinged on Tisch’s appointment.

“Everybody wants to have their agenda passed, right? I think being really thoughtful about when to hold fire, when to fire, when to be bold, when to hold back, and when to say what you feel so you’ll get the most support,” Konst said.

But Avila Chevalier said she is willing to work with anyone to advance her priorities.

“There is always something that two people can agree on. And that’s where I plan on starting because I think organising is about meeting people where they’re at,” Avila Chevalier said.

“There are so many folks who really want to see healthcare transformed in this country, who really want to see a moratorium on data [centres]. That is a bipartisan issue for so many.”