Thirty years ago, when Ramesh Kilawan’s Indo-Caribbean family moved to their home in South Ozone Park in Queens, only one other South Asian family lived on the quiet block. Today there are more than a dozen.

Over time, Mr. Kilawan’s community grew, as thousands of Muslim, Sikh and Hindu immigrants moved to nearby Jamaica and Richmond Hill, filling the streets with Caribbean roti shops, Indian grocers and temples.

But even as the influx transformed the neighborhoods into areas now known as Little Punjab and Little Guyana, few in the South Asian diaspora were deeply engaged in electoral politics until this year, when Zohran Mamdani’s bid for mayor began to catch fire.

Mr. Mamdani, a state assemblyman from Queens and a democratic socialist, emerged victorious in the Democratic primary in June, fueled in part by a novel, diverse coalition that included broad swaths of South Asian voters in New York.

The election signals a high-water mark for political participation among South Asian New Yorkers.

Turnout among South Asian voters increased by 40 percent compared with the 2021 primary, according to a New York Times analysis of voter records and demographic estimates based on voters’ names and neighborhoods from a nonpartisan data firm, L2.

The community still only represents a small share of voters. There are roughly 450,000 South Asians in New York City, about 5 percent of the population. They have typically made up a smaller share of the electorate than other ethnic constituencies, in part because a large share of the community is made up of noncitizens or those too young to vote. But the community has been growing rapidly, including a Bangladeshi population that has nearly tripled in the last decade.

Thousands of these voters registered for the first time this election cycle.

“I have never seen so much energy around a mayoral candidate,” said Sonny Singh, a Brooklyn-based musician and volunteer for Mamdani’s campaign whose family comes from Pune, India. “Groups that have historically been less inclined to get too involved electorally are stepping up.”

DRUM Beats, or Desis Rising Up and Moving, and CAAAV Voice, the Committee Against Anti-Asian Violence, engaged more than 150,000 South Asian residents across all five boroughs in the months leading up to the June primary, their leaders said. By Election Day, more than one-third of the city’s South Asian residents had been canvassed by these groups or Mr. Mamdani’s campaign itself.

Mr. Kilawan, a registered Democrat who rarely crosses party lines, said he had been prepared to vote for former Gov. Andrew M. Cuomo in the Democratic primary. Then, after a 15-minute conversation with a young canvasser for Mr. Mamdani, he changed his mind.

“Whether left wing, whether right wing, I don’t care,” Mr. Kilawan, a Hindu from Guyana, said. “What interested me was when he opened his mouth and said the policies of the guy.”

A 30-year veteran of the Metropolitan Transportation Authority, father of three and grandfather of three, he said he was impressed by Mr. Mamdani’s promises of free child care and free public transportation.

Mr. Mamdani has been viewed in some circles as a candidate whose path to victory relied largely on a young, white voting base. But his support among South Asians underscores how his campaign’s grass-roots outreach and longstanding relationships in these communities have allowed him to dramatically expand the electorate.

That any candidate could unite the city’s vast South Asian communities — who can trace their origins to more than six countries, speak dozens of languages and follow at least five religions — has long seemed implausible in a city as diverse as New York.

Prior election results have illustrated the difficulty of bringing these groups together. More than 20 South Asian Democratic candidates have unsuccessfully run for office over the last two decades. Few politicians from either party have tried meaningfully to engage South Asian voters: A 2022 Asian American Voter Survey found that 56 percent of respondents had “no or uncertain contact” from Democrats and two-thirds said the same of Republicans.

South Asian voters, like almost every other demographic group, have recently shown signs of a rightward shift. In 2024, more Indian Americans said that they would vote for Republicans than in 2020, according to research from the Carnegie Endowment for International Peace. In New York last November, Donald Trump made gains in heavily East and South Asian neighborhoods in Queens, while Democrats underperformed citywide, unable to turn out voters to the same extent as in past elections.

But less than a year after Mr. Trump won the presidency on a campaign that exacerbated tensions between established immigrants and recent arrivals, Mr. Mamdani, a Uganda-born Indian American, has pushed a different political narrative in New York City, one that focuses on a collective struggle against issues of affordability and inequality.

It has led him to be the front-runner in the race, and if elected, he will be the first South Asian and Muslim mayor of New York.

While most South Asian voters recognize the significance of having one of their own in office, they say they care much more about what he can deliver.

“It’s not like Zohran is the first Muslim or South Asian to run for elected office in New York City,” said Sasha Wijeyeratne, the executive director of CAAAV Voice. His appeal lies in his willingness to develop a platform that is “able to offer South Asians, particularly working-class South Asian voters, actual concrete material improvements in their lives.”

Beyond ‘photo-op uncles’

Mr. Mamdani’s appeal to so many new and infrequent South Asian voters rebuked the conventional political wisdom about once-untapped voting blocs, said John Mollenkopf, the director of CUNY’s Center for Urban Research. The political parties, he said, have long stuck to outdated assumptions about which voters to target and how much money to spend on outreach.

“The parties were ignoring them,” said Mr. Mollenkopf, who has studied immigrant voting patterns for decades. “They didn’t consider them prime voters, so they weren’t spending money.”

Mr. Mamdani’s campaign changed the calculus, relying on help from South Asian groups and organizations familiar with the candidate’s days as a Queens assemblyman. His campaign slogan in 2020 was “Roti and Roses,” signifying the two aspects that remain central to his politics: his South Asian community and his socialist platform.

Then, in the first months of his term in the State Capitol, he moved his legislative office to the site of a taxi workers’ protest and engaged in a hunger strike alongside activists and drivers.

“Some of my close friends as I grew up, their fathers were taxi drivers,” Mr. Mamdani said, recalling the experience. He said he had been frustrated with the pace of progress, which he saw as “a reflection of the lack of political power of the constituency that it was affecting.”

An explicit part of the strategy of Mr. Mamdani’s mayoral campaign has been to expand the political power of those same constituencies. “I wanted to ensure that every uncle, every auntie, across the five boroughs not only knew when the election was but received the outreach that the most reliable voter would receive,” he said. The decision to participate in elections, he said, is “driven by whether or not the campaigns that are contesting those elections are treating you with respect.”

Yet others said the effectiveness of the campaign’s outreach lay in its ability to mobilize beyond traditional South Asian community leaders, typically older men who act as gatekeepers and are sometimes jokingly referred to as “photo-op uncles,” because of their penchant for taking photos with politicians and other prominent figures.

Jagpreet Singh, the political director of DRUM Beats who is a close ally of Mr. Mamdani, said the group had employed a “pincer” tactic to curb the influence of such leaders.

“We were targeting community leaders, institutional leaders, being like, ‘Hey, look, your congregation, your members are already on board,’” Mr. Singh said, adding that he had made the case that endorsing Mr. Cuomo could be “‘an issue for you at the end of the day and your legitimacy.’”

Prominent community figures like Bangladeshi police officers, a growing constituency in New York City, have shown up in force for Mr. Mamdani. He has formed a close relationship with the family of Didarul Islam, the Bangladeshi police officer killed in a massacre at a Park Avenue office building in July.

Even as organizers sought to work around the traditional male community leaders, the Bangladeshi aunties, as Mr. Mamdani has affectionately called them, were on the job. The women knocked on doors and made phone calls for Mr. Mamdani and a Brooklyn-based Bangladeshi city councilwoman, Shahana Hanif, throughout the summer, sometimes completing volunteer shifts after leaving their day jobs and staying late into the night.

“Zohran’s campaign means a lot for our people. So that’s why purposely they dedicated their time,” Kazi Fouzia, DRUM Beats’s director of organizing, said in an interview at the organization’s office in Kensington, Brooklyn.

Mr. Mamdani’s steadfast criticism of Israel’s conduct in Gaza has been yet another galvanizing force in this electorate, at a time when a majority of the Democratic Party’s voters say they sympathize more with Palestinians than Israelis. Many South Asian New Yorkers say they strongly disagree with the use of tax dollars to fund weapons for Israel.

“It’s a pretty clear picture,” said Aadit Siwakoti, a Nepali organizer for DRUM Beats. Tax money, he said, is going to Israel “in the form of weapons to bomb and kill children.”

Jamila Wilkinson, 27, canvassed for Mr. Mamdani in the left-leaning neighborhoods of Manhattan’s Lower East Side, Ridgewood in Queens and Crown Heights in Brooklyn. Only later she realized that her grandmother, the renowned Indian cookbook author and actress Madhur Jaffrey, had starred with Mr. Mamdani in “Nani,” the music video that he produced as his rapper-alter-ego, Mr. Cardamom.

Ms. Wilkinson is among many who said it is folly to believe that representation is the main factor driving South Asians’ support for Mr. Mamdani.

A candidate like Mr. Mamdani “represented a change in this politics of cynicism and stagnation that was defining these other candidates and also New York politics,” she said.

The geopolitical backdrop

The strength and breadth of the coalition forming around Mr. Mamdani has stunned even the most hopeful of observers, including Zakarya Khan, the Pakistani American owner of the Gyro King franchise, which he founded from a food truck on Wall Street shortly after Sept. 11.

He has seen his business flourish and now runs nonprofits focused on empowering young Muslims. Still, he said he never thought that a Muslim socialist like Mr. Mamdani would be viable. He is pleased to have been wrong.

“I believe Zohran will actually start the process of building a pipeline for our future leadership,” Mr. Khan said.

Not everyone in the South Asian community has been won over, with visible rifts emerging in August during weekend events celebrating India’s and Pakistan’s independence.

That weekend, Mr. Mamdani — who has called India’s Hindu-nationalist Prime Minister, Narendra Modi, a “war criminal” — performed a delicate balancing act. He spent Saturday celebrating with Indians in Queens and Sunday with Pakistanis in Brooklyn. He did not attend Manhattan’s India Day Parade, the largest of the independence-day events.

Mayor Eric Adams attended the parade, waving to the crowds gathered on either side of Madison Avenue, as did Mousume Sarker, 54, who said she would never vote for Mr. Mamdani.

“First, he will go and defund the police,” she said. “And second thing, he’s going to give everybody rent, you know, he’s going to stop rent increases. That will not help the city.”

Ms. Sarker, a Hindu originally from Bangladesh, said that while Mr. Mamdani’s plan for New York City matters most to her, she also objected to his criticism of Mr. Modi, which she perceived to be motivated by anti-Hindu sentiment. Mr. Mamdani’s mother is Hindu, and though his campaign has said that the religion “is a meaningful part” of his life, he has been endorsed by only one major Hindu organization, Hindus for Human Rights.

In an interview, Mr. Mamdani defended his comments about Mr. Modi, saying they were “a reflection of my belief in universal human rights.” Under Mr. Modi, Muslims have been increasingly marginalized in India.

In June, the New York chapter of the American Hindu Coalition endorsed Mr. Cuomo for the primary. The same month, Hindu groups paid for three different aerial banners to fly over the Hudson River, urging voters to support Mr. Cuomo and reject Mr. Mamdani. Even though two of the banners’ financial backers reside out of state, in New Jersey and Texas, they made local and global headlines, and videos of them circulated online.

The New York Hindu group has since endorsed Mayor Adams for the general election.

These efforts to influence the campaign disturbed some Indian American New Yorkers who do not support the rise of Hindu nationalism in India.

“If that is imported here, it could fuel something that’s going to divide us in a way that we have not seen before,” said Lavanya DJ, 45, a communications executive and Manhattan resident who supports Mr. Mamdani.

Ms. DJ joined other Hindu New Yorkers to start a new group called “Hindus for Zohran.” They had a launch party this summer that was also sponsored by several grass-roots South Asian and professional groups that had formed to support Mr. Mamdani’s campaign. After their first venue sold out, they changed locations to a larger space in Greenpoint, Brooklyn, which also sold out.

That night, musicians sang in Arabic, Urdu and Hindi, mentioned Palestinian suffering in Gaza and performed “We Will See,” a poem by the dissident Pakistani poet Faiz Ahmad Faiz.

“He unites people,” said 29-year-old Sneha Jayaraj, a lawyer who had arranged the evening’s performances. “Not only New York City, the world needs that, you know?”

Pranav Baskar contributed reporting.