When Micah Lasher, an heir to the Manhattan Democratic establishment, won the primary in New York’s 12th Congressional District on Tuesday night, Gov. Kathy Hochul was by his side.
“They said that experience didn’t matter in Democratic politics,” the city comptroller, Mark Levine, told Mr. Lasher. “And you have proven that it does!”
Standing silently among the crowd of Democratic luminaries, Ms. Hochul held her steely smile — as if aware that across the state, celebrations of a different breed of politics were taking place.
Across New York City, candidates backed by Mayor Zohran Mamdani routed mainstream Democratic candidates, sending incumbents packing and bolstering the political power of the ascendant left. All three of the mayor’s preferred congressional candidates, all members of the Democratic Socialists of America, sailed to primary victories, two of them over incumbents backed by Ms. Hochul herself.
The results sent an unmistakable message to Ms. Hochul, who is seeking re-election this year against Bruce Blakeman, the Nassau County executive and supporter of President Trump, about where power now resides.
“The message and the framing and the vision that was laid out by the mayor in his campaign last year are the message and vision and framing that Democratic voters are clamoring for,” Amit Bagga, a strategist and a former member of the Hochul administration, said noting the socioeconomic and geographic diversity of voters who backed progressives in the primary.
“If I am the governor, I am also thinking very carefully about what this means with respect to the dynamic between myself and the State Legislature going into next year,” he said.
Ms. Hochul has been successful thus far at walking the tightrope of appeasing Mr. Mamdani and his base without relinquishing leverage. But with as many as 16 new D.S.A.-backed Democrats in the Legislature from all corners of the state, and with the mayor’s growing political clout, Ms. Hochul may find her own hand somewhat weakened — particularly on thorny issues like taxes.
New York City is facing a significant future budget gap and needs a reliable funding stream for the child care expansions Ms. Hochul and Mr. Mamdani ushered in this year. Mr. Mamdani’s other priorities — including free buses and city-run grocery stores — will also require investment.
Ms. Hochul has thus far resisted raising taxes, which she has said she considers a last resort.
But the governor — whose canny navigation of party politics helped to sink the campaign of her Democratic challenger, Lt. Gov. Antonio Delgado, before it took off — may sense which way the wind is blowing.
Ms. Hochul’s allies point to her success in engaging with Mr. Mamdani, not only on child care but also on a tax on second homes worth more than $5 million, as a model for other moderates.
“That was a great example of working with someone who is much more progressive, finding commonality and doing good for New Yorkers,” said Christine Quinn, the former speaker of the City Council and a Democratic Party executive committee chair.
“Anyone who has underestimates her does so at their own peril,” Ms. Quinn added.
In his postmortem news conference on Wednesday, Mr. Mamdani praised the winners of congressional and state legislative primaries who he said would be “partners” in his work.
Asked whether the results had reset the balance of power between the city and Albany — and, by default, himself and Ms. Hochul — he demurred.
“Their successes represent a shift in the balance of power between working people and special interests,” Mr. Mamdani said.
The productive partnership between Ms. Hochul and Mr. Mamdani belies the depth of disagreement between them on matters of policy.
A moderate from Buffalo who watched firsthand as her father’s successful career helped transform her family’s lives, Ms. Hochul has been a champion of economic development and a staunch ally of the business community. Many of those same businesses have turned around and supported her right back with campaign donations that have earned her the distinction of being one of the best political fund-raisers in the country.
Her reluctance to propose new taxes not only puts her at odds with Mr. Mamdani ideologically, but also threatens the many expensive programs that he has promised supporters he will fund with them.
And while Mr. Mamdani held off on openly challenging Ms. Hochul after she found several billion dollars to help him begin to realize one of his signature achievements, child care, there are indications that the left will be considerably less restrained next year.
On Wednesday, Grace Mausser, a co-chairwoman of the New York City D.S.A., had some advice for Ms. Hochul: The governor should realize, she said, that “running on a record that doesn’t appeal to people is not an effective strategy.”
Already, Republicans have begun to try to drive a wedge between the center and the left of the Democratic Party ahead of November, accusing the Democrats of being hijacked by Mr. Mamdani and his progressive ideals. “ Why won’t Kathy Hochul stand up to these radicals?” Ed Cox, the state Republican Party chair, said in a statement, calling the three newly elected democratic socialists supporters of “Islamic terrorism” who “want to dismantle the nuclear family.”
Mr. Mamdani dismissed the notion that socialists’ victories could be a liability for Democrats in November. “Finally working people are going to have more of a voice,” he said.
For her part, Ms. Hochul said she welcomed the energy insurgent candidates brought to the primary. “I’ve been involved in this political party my entire life,” she said. “No one has ever accused us of being fully united behind one individual, one concept. That’s OK. We speak for many voices.”
Jeffery C. Mays contributed reporting.
