Socialist Stunner: Mamdani Topples Cuomo in NYC Democratic Primary Earthquake

Paul Riverbank, 6/26/2025Socialist challenger Mamdani shocks NYC by defeating Cuomo in Democratic mayoral primary.

I've covered NYC elections for twenty years, and I've never seen anything quite like this. Mamdani, a 33-year-old Queens assemblyman who still rides the N train to Albany, somehow managed to outmaneuver one of the most powerful political machines in modern Democratic politics.

The numbers tell part of the story. In Harlem, where Cuomo's father Mario once held court like political royalty, Mamdani didn't just win – he dominated. "Lost Harlem? We got crushed there," one shell-shocked Cuomo advisor told me over coffee this morning at Junior's. The victory margins in progressive enclaves like Park Slope were expected. The breakthrough in traditional Democratic strongholds wasn't.

The reaction has been swift and predictable in some quarters. Donald Trump's Truth Social post calling Mamdani "a 100% Communist Lunatic" was vintage Trump – all heat, no light. More telling was the quiet panic among Democratic strategists I spoke with yesterday. "This isn't just a New York story," one veteran consultant texted me at midnight. "Every swing district Democrat just got handed a messaging nightmare."

But the real drama may be yet to come. The November election now features a three-way race that would have seemed impossible a year ago: Mamdani carrying the Democratic banner, Eric Adams running as an independent, and Curtis Sliwa representing the Republicans. Sliwa, never one to miss a quotable moment, vowed to stay in the race until he's "in a pine casket 6 feet under."

The business community's reaction has ranged from unease to outright alarm. At a private dinner in Midtown last week, I listened as CEOs and real estate developers gamed out scenarios for dealing with Mamdani's proposed wealth tax and his plans to expand rent control. "We survived de Blasio," one developer said, "but this is different."

What makes this moment particularly fascinating is how it tests the Democratic Party's ability to hold together its increasingly divergent coalitions. The party that produced both Joe Biden and AOC now faces a mayoral nominee who makes AOC look moderate by comparison.

The weeks ahead will reveal whether Mamdani can expand his coalition beyond the progressive base that delivered his primary victory. History suggests it's an uphill battle – but then again, history suggested he couldn't win the primary either.

I've learned over decades of covering politics that the safest prediction is usually that things will somehow muddle through. But watching the faces at Democratic headquarters last night, I'm not so sure that's the safe bet anymore. New York City politics just entered uncharted territory, and no one – not even those of us who've covered this beat for decades – can confidently predict where this ride ends.

New York's political earthquake arrived yesterday with all the subtlety of a midnight subway train. Zohran Mamdani's stunning victory in the Democratic mayoral primary didn't just defeat Andrew Cuomo – it shattered decades of conventional wisdom about what's possible in Big Apple politics.I've covered NYC elections for twenty years, and I've never seen anything quite like this. Mamdani, a 33-year-old Queens assemblyman who still rides the N train to Albany, somehow managed to outmaneuver one of the most powerful political machines in modern Democratic politics.The numbers tell part of the story. In Harlem, where Cuomo's father Mario once held court like political royalty, Mamdani didn't just win – he dominated. "Lost Harlem? We got crushed there," one shell-shocked Cuomo advisor told me over coffee this morning at Junior's. The victory margins in progressive enclaves like Park Slope were expected. The breakthrough in traditional Democratic strongholds wasn't.The reaction has been swift and predictable in some quarters. Donald Trump's Truth Social post calling Mamdani "a 100% Communist Lunatic" was vintage Trump – all heat, no light. More telling was the quiet panic among Democratic strategists I spoke with yesterday. "This isn't just a New York story," one veteran consultant texted me at midnight. "Every swing district Democrat just got handed a messaging nightmare."But the real drama may be yet to come. The November election now features a three-way race that would have seemed impossible a year ago: Mamdani carrying the Democratic banner, Eric Adams running as an independent, and Curtis Sliwa representing the Republicans. Sliwa, never one to miss a quotable moment, vowed to stay in the race until he's "in a pine casket 6 feet under."The business community's reaction has ranged from unease to outright alarm. At a private dinner in Midtown last week, I listened as CEOs and real estate developers gamed out scenarios for dealing with Mamdani's proposed wealth tax and his plans to expand rent control. "We survived de Blasio," one developer said, "but this is different."What makes this moment particularly fascinating is how it tests the Democratic Party's ability to hold together its increasingly divergent coalitions. The party that produced both Joe Biden and AOC now faces a mayoral nominee who makes AOC look moderate by comparison.The weeks ahead will reveal whether Mamdani can expand his coalition beyond the progressive base that delivered his primary victory. History suggests it's an uphill battle – but then again, history suggested he couldn't win the primary either.I've learned over decades of covering politics that the safest prediction is usually that things will somehow muddle through. But watching the faces at Democratic headquarters last night, I'm not so sure that's the safe bet anymore. New York City politics just entered uncharted territory, and no one – not even those of us who've covered this beat for decades – can confidently predict where this ride ends.