Analysis: NYC 2025 Mayoral Election

Executive Summary

AARP New York engaged Gotham Polling & Analytics to produce a research brief examining voter registration and turnout dynamics in the 2025 New York City mayoral primary, with emphasis on generational patterns and their implications for the upcoming general election. Drawing on official Board of Elections data and L2 voter files, the analysis tracks first-time voters, new registrants, and turnout trends across the 2017, 2021, and 2025 cycles. The results point to an unprecedented surge of under-50 participation in 2025, overturning the long-standing dominance of voters age 50+, and raising key questions about whether this youth-driven shift is a one-time anomaly or a lasting realignment in New York City politics.

Key Takeaways

• Youth Surge Delivers Upset Primary Victory: In the June Democratic primary, 33-year-old Assemblyman Zohran Mamdani scored a stunning win, powered by an unprecedented surge in younger voters. For the first time in recent memory for any primary election, under-50 voters actually comprised a majority (51%) of Democratic primary turnout, up from just 41% in 2021. Meanwhile, the share of voters age 50+ fell below half – a dramatic departure from past NYC elections where older voters dominate. An Election Day heat wave (nearly 100°F) may have suppressed older turnout while Mamdani’s youthful base braved the heat in force.
• Mamdani Leads a Fractured Field: As the race turns to November, Mamdani holds a commanding lead in a five-way general election contest – but with only pluralistic support. A AARP/Gotham poll conducted in August finds Mamdani at 41.8%, well ahead of former Governor Andrew Cuomo (23.4%), Republican Curtis Sliwa (16.5%), incumbent Mayor Eric Adams (8.8%), and others. Mamdani’s ~42% “hard floor” reflects a loyal progressive base, but also a firm ceiling below a majority in this deep-blue city. Nearly 58% of voters prefer “Anyone-But-Mamdani,” split among three high-profile rivals. This fractured opposition currently enables Mamdani to lead with well under half the vote.
• Older Voters Could Tip the Balance: Although Mamdani maintains an edge in every scenario tested, voters age 50+ emerge as the potential kingmakers. In a hypothetical head-to-head matchup with Cuomo (all other candidates dropped), Mamdani’s lead shrinks to 11 points (42% to 31%), with fully 27% of voters still undecided. Crucially, nearly eight in ten of those undecideds are over age 50. This older, mostly moderate bloc could swing decisively – they are the voters most skeptical of the young insurgent and most resistant to him in polls. If they break heavily against Mamdani, and if older adults return to their usual high turnout levels (historically 60%+ of NYC general electorates), the dynamic shifts dramatically. Internal modeling suggests that if 50+ voters make up ~56% or more of November’s voters (closer to normal levels) – and consolidate behind a single opponent – Mamdani could actually be vulnerable to an upset. Conversely, if the youth-driven turnout patterns of the primary persist, Mamdani remains the clear favorite.
• High Stakes and Pressure to Consolidate: These findings upend the assumption that a Democrat is automatically safe in NYC’s general election. They indicate a plausible (if challenging) path for a centrist challenger to defeat Mamdani, a scenario few anticipated. Such an outcome would reverberate nationally. Expect growing pressure on trailing candidates to unify the anti-Mamdani vote. Indeed, Cuomo has openly urged that any contender not leading by early fall should drop out and back the runner-up. (So far Adams and Sliwa refuse to bow out.) The prospect of a divided field handing City Hall to a far-left nominee may spur last-minute dealmaking. According to reports, Trump advisers have even floated offering Mayor Adams a job in a future administration if he quit the race to boost Cuomo’s chances. In short, New York’s normally predictable mayoral general election has become an unprecedented wildcard, with older voters poised to play the decisive role.

Conclusion: An Unprecedented Showdown

New York City’s 2025 mayoral race has evolved from a once-assumed coronation of the Democratic primary winner into a genuinely intriguing, competitive contest. The primary upset by Zohran Mamdani injected uncertainty and excitement into what is usually a foregone conclusion in this deep-blue city. Now, with the general election looming, the narrative has shifted: it’s no longer “Can a Democrat win in NYC?” (that’s almost given), but rather “Which vision of the Democratic Party will lead the city – and could a coalition of disaffected Democrats, independents, and Republicans thwart the left-wing insurgent?”

The data and analysis above indicate that Mamdani is favored but not invincible. His roughly 40% base of enthusiastic supporters will carry him far. Yet roughly 60% of voters prefer someone else, and they could unite under the right conditions. The importance of voters aged 50 and above cannot be overstated in determining which scenario plays out. They will likely comprise a majority of November voters, and they disproportionately populate the undecided and persuadable category right now. Mamdani has already proven the ability of young voters to upend New York’s political calculus – but can he overcome the historical might of the senior vote in a general election? That is the central question as the campaign enters its final stretch.

For the media and political observers, the potential for an upset – a progressive Democrat falling to an independent or a fusion-backed candidate in New York City – is the story to watch. It has been decades since NYC saw a truly competitive general mayoral election pitting a Democrat against a strong independent bid. A Cuomo victory (or even a close finish) would signal a remarkable realignment, driven largely by older voters’ backlash against a progressive agenda. Even the possibility of that outcome is already influencing behavior: pressure is mounting on lower-polling candidates to bow out, and Mamdani, who ran as an uncompromising progressive, is now making more moderate overtures to broaden his appeal to older voters and party stalwarts.

One way or another, the 50+ voters will likely decide this election: either by turning out in force to deliver a check on the progressive wave, or by remaining split (or staying home) and allowing the youth-fueled Mamdani coalition to prevail. As AARP New York’s survey press release put it, Mamdani holds a “commanding lead” for now, “but older undecided voters could emerge as a key swing bloc.” Those older swing voters will be hearing plenty from all sides in the coming weeks.

The general election is set for November 4, 2025. Between now and then, New Yorkers can expect an intense campaign aimed particularly at their parents and grandparents. Will New York embrace a new, youthful progressive era, or will the city’s formidable older electorate assert a preference for experience and moderation? The answer will shape not just the city’s future, but could send a signal nationwide about the direction of the Democratic Party. All eyes will be on the behavior of those crucial senior voters come Election Day.