Free Buses and Child Care. A Rent Freeze. Can Zohran Mamdani Achieve His Plans?

Zohran Mamdani’s rapid rise from upstart mayoral hopeful to likely winner of the Democratic primary for mayor of New York City was propelled by the simple message that the city was too expensive — and that he had plans that would fix it.

Mr. Mamdani’s singular focus on the city’s affordability crisis resonated, especially with young voters. They embraced his populist promises to make bus service free, freeze rents on stabilized apartments, build city-owned grocery stores and offer free early child care.

But whether his campaign promises can become reality is an open question — and important parts of Mr. Mamdani’s platform are not solely in a mayor’s control.

While some of his left-leaning policy ideas are not entirely new — rents have been frozen before, for example — others would represent a dramatic reimagining of city government.

And much of Mr. Mamdani’s agenda relies in large measure on increasing revenue through taxes on businesses and the wealthy — part of an overarching vision to rethink how the city funds expanded social programs. Along with raising income taxes, he has pledged to shift the property tax burden “from the outer boroughs to more expensive homes in richer and whiter neighborhoods,” according to his campaign website.

Already, Mr. Mamdani’s plans, in line with his democratic socialist political affiliation, have prompted intense backlash from business leaders who say he poses a danger to New York’s economy. In private meetings, power brokers are discussing how to mount a strong challenge to Mr. Mamdani in the November general election.