After donors poured millions into Cuomo’s campaign, a grassroots movement helped fuel Mamdani’s upset victory

Ten days before New York City’s Democratic primary, Michael Bloomberg transferred $5 million to Andrew Cuomo’s super PAC. On prediction market Polymarket, Zohran Mamdani’s odds collapsed from 42 percent to 25 percent, while Cuomo surged to 73 percent. Many political insiders assumed the race was decided.

What they didn’t anticipate was a former Airbnb executive about to spend his Wednesday afternoon making phone calls.

Rehan Azhar had never donated to a political campaign. After selling his healthcare company Comprehensive Rehab Consultants to York Private Equity in 2023, he’d established a donor-advised fund focused on schools, domestic violence shelters, and community centers: tangible projects where impact could be measured in square footage. Politics felt murkier, less certain of return.

But watching those numbers fall, he started texting.

Within 24 hours, Azhar and the network he mobilized had pledged over half a million dollars. His own contribution eventually reached over $150,000, among the largest donations to Mamdani’s super PAC during the primary push. A Silicon Valley angel investor also making his first political donation, told ABC News he saw financial support as a way to secure visibility for his community. “Maybe this is the infancy of something to come,” he said.

Six days later, Mamdani won by 12 points.

Mobilizing Outside Traditional Structures

Mamdani’s surprise victory revealed how modern campaigns can benefit from donor networks that operate outside traditional party infrastructure, activate rapidly, and represent communities that have historically remained on the political sidelines.

Waleed Shahid, a Democratic strategist, noted that “most immigrant communities in the U.S. follow a familiar trajectory in their giving: it starts with religious institutions and charity.” 

Electoral politics comes later, if at all. Focusing donations on campaigns and candidates can take generations. The Mamdani campaign compressed that timeline dramatically.

According to Bloomberg News, Mamdani attracted over 20,000 donors during the primary, the most since 2001 aside from Andrew Yang’s 2021 run. Between June 25 and July 11, the campaign brought in over $800,000 from more than 10,000 donors, with roughly $350,000 raised outside of New York City.

Tech workers emerged as unexpected allies: 260 Google employees contributed nearly $40,500. The Council on American-Islamic Relations’ political arm contributed $100,000. Rocket Money co-founders Haroon and Idris Mokhtarzada gave over $189,000. Celebrities including Emily Ratajkowski, comedian Ramy Youssef, and musician Lorde amplified his message on social media.

Asif Mahmood, who ran for Congress and now supports Mamdani, observed that the candidate “was able to move Muslim support across the board.” Mahmood pointed to how Mamdani united constituencies that rarely align in electoral politics: Arab and South Asian donors, religious and secular Muslims, contributors from New York and across the country.

For Azhar, the decision to contribute came down to representation without tokenization. Mamdani centered his campaign on policy issues like rent freezes, free buses, and affordable childcare. He openly embraced his Muslim identity without treating it as his main qualification. 

“He didn’t shy away from his culture and his background, but he also didn’t really dive into identity politics,” Azhar explained in an interview. “He said his piece and outlined his policies, and then he said, also, I’m these things.”

Small Donations, Amplified

The fundraising mechanics tell their own story about how grassroots donations can compete with billionaire spending when amplified by public financing. New York City’s 8:1 matching system meant Mamdani’s small-dollar contributions unlocked millions in public funds. Bloomberg alone put over $8 million into Cuomo’s Fix the City PAC, which spent over $22 million during the primary. Mamdani still won.

That outcome is reverberating across U.S. politics. It demonstrates that donor infrastructure built around authentic engagement, where thousands feel ownership because they helped fund the campaign, can overcome traditional financial advantages.

Seth Masket, who studies politics at the University of Denver, suggested the victory reflects “a vibe that’s going on across the country where a lot of Democratic voters seem to be souring on the party’s leadership, the party’s establishment, and are looking for unusual different voices to lead them going forward.”

Beyond One Election

Whether that analysis holds may matter less than the infrastructure being built. Phone trees that activated in June still work. Donors who contributed for the first time now know how. Group chats that hummed with political strategy haven’t necessarily gone quiet.

Other cities with large Muslim American populations are watching. So are progressive organizers in districts where establishment candidates have long run unopposed. The question is whether the donor networks that supported Mamdani can be activated again for down-ballot candidates, state legislative races, congressional primaries.

Recent polling from Quinnipiac University shows Mamdani with 45% of likely voters in the upcoming mayoral elections, 20 points ahead of Cuomo, who is now running as an independent. Prediction markets place his odds above 90 percent. The November 4 general election will determine whether he becomes mayor. But the hope is that the networks formed during the primary persist regardless of the outcome.

Azhar’s giving philosophy has always centered on sustainable impact, projects that compound over time. He prefers funding real estate for nonprofits because buildings endure. The political infrastructure from this campaign may prove similarly durable, though harder to quantify.

What happened in those 24 hours after Bloomberg’s $5 million infusion was proof that communities long relegated to spectator status in American politics could become participants, and when they did they could swing elections.

The forces arrayed against Mamdani remain formidable. Business leaders have expressed concern about his tax proposals. President Trump has attacked him on social media. Well-funded opposition groups continue organizing. 

But what happens to the donor networks that mobilized for him may determine something larger: whether a new generation of Americans, including previously disengaged young people, believes politics is worth their money, their time, their sustained attention.

For many of them, June 24 already answered that question. Now they’re watching to see who runs next.