Zohran Mamdani’s victory in the Democratic primary for New York City mayor was a massive, earth-shaking upset. When he announced his campaign last October, insiders scoffed: “Could this pro-Palestinian socialist really be NYC’s next mayor?” ran the headline at City & State. For Politico’s New York Playbook, he was little more than “a longshot,” whose presence in the race might damage established progressives like Brad Lander or Jessica Ramos. Less than a month ago, betting markets gave him a 6 percent chance of defeating the heavy favorite Andrew Cuomo.

Mamdani won anyway — not by eking it out in the seventh round of ranked-choice voting, but topping Cuomo among first-choice ballots and claiming outright victory on election night. His triumph sends a clear message: a bold populist campaign and a laser-like focus on economic issues can break through to voters, even when insiders, billionaires, and the party establishment line up in opposition. Mamdani’s stunning victory offers some vivid lessons for left-wing politics, both in New York City and beyond.

For progressives, the race was a strong vindication of the economic-populist strategy we have long advocated in our work at the Center for Working-Class Politics (CWCP). As CWCP research associates Matt Karp and Dustin Guastella wrote in a 2021 Guardian article, to win, Democrats must “embrace bread and butter economic issues.” And unlike many other progressive candidates over the last five years, that’s exactly what Mamdani did. His campaign was highly disciplined, with a tight focus on housing, transportation, wages, and the everyday cost of living. That message reached not just core progressive constituencies, but many working-class New Yorkers, who have traditionally shied away from progressive challengers or sat out Democratic primaries altogether.

Crucially, Mamdani took a pragmatic approach on issues that have tripped up many other left challengers. He distanced himself from “defund the police” rhetoric without disowning public safety reform, and avoided activist jargon that can turn off more moderate or apolitical voters. The result was a campaign that resonated in places where earlier progressives had faltered. Mamdani outperformed previous left-liberal candidates in many working-class neighborhoods, and his platform’s emphasis on cost-of-living issues likely helped bring low-frequency voters off the sidelines. Indeed, turnout surpassed one million — a higher total than any of the past six mayoral primaries.

Mamdani’s economics-focused, ideologically pragmatic approach is especially important because low-frequency Democratic voters tend to be both less ideologically progressive and more economically precarious than consistent voters. Mamdani’s apparent success in mobilizing many of these voters suggests that an economics-first message can help progressives expand the electorate beyond the usual suspects.

There are lessons here for Democrats more broadly as well. First, being anti-Trump is not enough. As Bernie Sanders wrote, Mamdani’s win shows that “we have to bring forth a positive vision and an analysis of why things are the way they are.” This is consistent with CWCP’s own polling in the critical swing state of Pennsylvania, which showed that 2024 voters were much more likely to be persuaded by positive economic populist appeals than negative attacks on Trump as a threat to democracy (however real those threats may be).

Second, charisma and communication matter. Unlike many Democrats, including, famously, Kamala Harris, Mamdani is highly effective at retail politics and adept at reaching voters where they are—whether on the street through his impressive canvassing operation, online through creative, relatable, and often funny short videos, or through long-form podcasts. He was able, unlike most Democrats, to craft an image that felt both relatable and authentic at a grassroots level.

And finally, Mamdani’s win is a clear indication — if another were needed — that the Democratic establishment is badly out of touch. Its near-unanimous opposition to Mamdani echoed its circle-the-wagons resistance to Sanders in 2020 and reinforced the image of a party elite disconnected from its own base. Long-time New York Democratic Rep. Jerry Nadler called Mamdani’s win a “seismic election for the Democratic Party that I can only compare to Barack Obama’s in 2008.” Mamdani’s victory should (though sadly will likely not) serve as a wake-up call to Democrats:  the energy, ideas, and electoral potential that many Democrats claim to be searching for are already here, but mainstream Democrats just haven’t embraced them.

At the same time, it is important to be clear about what Mamdani’s victory does and does not suggest about progressive politics more broadly, particularly outside Democratic strongholds like New York City. First, Mamdani’s victory in no way suggests that progressives everywhere can campaign as far left as possible on divisive social issues and still break through to working-class voters. On the contrary, Mamdani’s own strategy reflects an awareness of these limits: he took care to distance himself from earlier positions, like “defund the police,” that might have diverted attention away from his core economic message.

It is impressive that Mamdani prevailed despite a barrage of attacks against him, but this hardly means that he would have been similarly effective in a purple or red district. Indeed, Mamdani overcame pushback against some of his more controversial stances in large part because the electorate he faced was quite progressive, and therefore comparatively forgiving.  The Democratic primary electorate in New York City contains an unusually high share of college-educated voters, as much as 55 percent. These voters, who are substantially more progressive on social and cultural issues than noncollege graduates, make up only about 35% of general election voters in key swing states. It’s hard to imagine Mamdani overcoming the same attacks in that kind of electoral setting.

While college-educated voters may be sufficient to win a New York City Democratic primary, that is not at all the reality in key swing states and districts where the numbers simply don’t add up. The coalition that carried Mamdani — renters, service workers, and progressive professionals — is a real and growing one. But it’s not large enough to win national elections or even many statewide contests. To build the national coalitions we need to stop Trumpism and deliver meaningful gains to working people, progressives still have to grapple with how to win back the many working-class voters of all backgrounds they have lost over the past decades. There is no shortcut to this struggle.

None of this is to take away from Mamdani’s win. While the campaign may not be a one-size-fits-all model for every battleground district, it marks a watershed moment for the Left — arguably the most significant electoral breakthrough of this generation of progressive politics. It’s a powerful testament to how far a clear, grounded, and economically focused campaign can go, even against a well-funded and deeply entrenched opposition.