New York state assemblyman Zohran Mamdani will become the mayor of New York City in January after running a seemingly impossible campaign for Gracie Mansion. The left-wing Millennial, who is calling for extensive tax hikes on the wealthiest New Yorkers, defeated Governor Andrew Cuomo, who ran as an independent, and Republican nominee Curtis Sliwa. 

Mr. Mamdani won four of the city’s five boroughs — all except Staten Island — with either a majority or a plurality of the vote. Decision Desk HQ predicted that Mr. Mamdani had won the race just 30 minutes after polls closed on Tuesday. CNN and NBC News projected the same outcome shortly thereafter. 

According to an exit poll from CNN, Mr. Mamdani struggled with non-college educated and Jewish voters in the city. That survey found that 42 percent of voters with no college degree backed Mr. Cuomo compared to 38 percent who supported Mr. Mamdani. Among Jewish voters, Mr. Cuomo prevailed by a two-to-one margin, with 60 percent backing the ex-governor and 31 percent supporting Mr. Mamdani. 

The assemblyman, who will take office on January 1, 2026, as the youngest mayor in more than a century, has become well-known in recent months for his left-wing stances on everything from taxation to policing to universal government programs. President Trump went so far as to endorse Mr. Cuomo on Monday night in the hopes of blunting Mr. Mamdani’s rise. 

Especially concerning for many New Yorkers — especially Jewish citizens of the city — was Mr. Mamdani’s stance on Israel and the war at Gaza. He often stated that he would not condemn the phrase “Globalize the Intifada,” and said that he would arrest Prime Minister Benjamin Natanyahu should he arrive in the city. 

A former mayor of New York City, Bill de Blasio, said on a CNN panel on Tuesday that Mr. Mamdani exhibited “perfect message discipline” and a focus on “kitchen table issues” during his campaign. Mr. de Blasio endorsed Mr. Mamdani after he won the primary in June. 

“When you look at all the pieces that make up a great campaign, there’s basically nothing missing here,” Mr. de Blasio said. “It’s a generational struggle,” he added, arguing that young people in the city moved so far to the left because of affordability issues. 

Mr. de Blasio’s fellow prominent Democrats, however, have shied away from Mr. Mamdani’s campaign. Senator Chuck Schumer has consistently kept his mayoral vote private, despite the fact that he is arguably the most powerful Democrat in the country. 

“Look — I voted and I look forward to working with the next mayor to help New York City,” Mr. Schumer told reporters on Tuesday at the Capitol when asked if he had voted for Mr. Mamdani. 

The House minority leader, Congressman Hakeem Jeffries, pushed his endorsement of Mr. Mamdani until the very last moment. In a statement released less than two weeks before the election, Mr. Jeffries praised Mr. Mamdani’s focus on bringing down the cost of living. 

“For decades, working class neighborhoods of color have been hurt by gentrification and housing displacement. That must change,” Mr. Jeffries said on October 24. “I support our nominee’s strong commitment to building a City where everyday New Yorkers can afford to live.”

Some key national Democrats gave more support to Mr. Mamdani than his own neighbors in the city. President Obama’s team told the New York Times that the former president had called Mr. Mamdani and told him that he was supportive of his “impressive” campaign. Mr. Obama reportedly offered to be a “sounding board” for the new mayor. 

Vice President Kamala Harris, too, spoke to Mr. Mamdani to offer support for his candidacy. During a book tour event in the city back in September, Ms. Harris said that she had called Mr. Mamdani to praise him for “bringing people in” and “showing that there are voices that want to be heard.”