Former Mayor Michael R. Bloomberg on Tuesday announced that he was backing former Gov. Andrew M. Cuomo in the New York City mayor’s race, giving Mr. Cuomo an endorsement coveted by many of the Democratic candidates in the race.
Mr. Bloomberg said in a statement that it had been difficult to watch the city struggle since he left office, especially during the coronavirus pandemic, and that Mr. Cuomo was the best choice for mayor. He called Mr. Cuomo a “pragmatist” and praised his work to rebuild LaGuardia Airport.
“In sizing up the field in the race for mayor,” Mr. Bloomberg said, “there is one candidate whose management experience and government know-how stand above the others: Andrew Cuomo.”
Mr. Bloomberg has a long record of helping Democratic candidates. He spent heavily in the 2018 midterms, gave President Joseph R. Biden Jr. $20 million in 2024 and kicked in $50 million toward Vice President Kamala Harris’s election effort.
But he has mostly avoided endorsing mayoral candidates at the primary level in New York City, making his backing of Mr. Cuomo more notable.
It was not immediately clear if Mr. Bloomberg intended to further assist Mr. Cuomo during the last two weeks of the race by hitting the campaign trail with him. But according to a person familiar with his thinking, Mr. Bloomberg is expected to contribute to a group allied with Mr. Cuomo.
Many moderate voters look back fondly on Mr. Bloomberg’s three terms in office and are interested in a candidate who might have better managerial skills than the current officeholder, Mayor Eric Adams.
Mr. Cuomo has centered his campaign on the notion that he is the most qualified candidate to help rescue the city from what he perceives as a crisis related to quality-of-life concerns, and Mr. Bloomberg’s assessment may help.
The endorsement may also persuade some undecided voters who have criticisms of Mr. Cuomo’s handling of the pandemic or who may have misgivings over his sexual harassment scandal, which led to his resignation as governor of New York in 2021.
Ester R. Fuchs, a political science professor at Columbia University and a former adviser to Mr. Bloomberg, said the endorsement could sway voters who were on the fence about Mr. Cuomo.
“Bloomberg is the most critical and important endorsement for Cuomo in the primary,” she said. “It’s a seal of approval for moderate voters who care about effectively governing the city.”
Mr. Cuomo has led in polls ahead of the June 24 Democratic primary. But he has faced a surprisingly strong challenge from Zohran Mamdani, a state lawmaker from Queens and a democratic socialist.
Mr. Mamdani’s campaign said in a statement that “billionaires are consolidating around Andrew Cuomo because they know he will preserve the broken status quo.”
“New Yorkers are rallying behind Zohran Mamdani because they are ready for a new generation of leadership that puts working people first,” the statement said. “On June 24, we will shock the political establishment and win a city we can all actually afford.”
The endorsement comes two days before the second and final candidate debate on Thursday. Representative Alexandria Ocasio-Cortez endorsed Mr. Mamdani last week, and polls show the race narrowing.
Mr. Bloomberg said that Mr. Cuomo had “focused on solving problems rather than engaging in ideological or partisan warfare,” a seeming reference to left-leaning candidates like Mr. Mamdani.
Mr. Bloomberg and Mr. Cuomo had a tense relationship when they overlapped in office more than a decade ago. They fumed privately about each other’s ego, as well as matters of style and substance.
Mr. Bloomberg referred to their past in the statement and said that there was no “perfect choice” in the race.
“History holds endless examples of friction between mayors and governors,” Mr. Bloomberg said. “During my 12 years in City Hall, I served with four New York governors and had differences with all of them, including Cuomo. But I also know his strengths as a leader and manager.”
Several of Mr. Bloomberg’s allies had donated to Mr. Cuomo’s mayoral bid, including his daughter Emma Bloomberg, indicating that the former mayor might be inching toward an endorsement.
In a series of interviews with the mayoral candidates, many praised Mr. Bloomberg as a manager, even if they criticized parts of his record, including a rise in stop-and-frisk policing during his administration.
Mr. Mamdani said that Bill de Blasio had been the best mayor in his lifetime and he praised Mr. de Blasio’s implementation of universal prekindergarten. Mr. Cuomo said that Mr. Bloomberg “was the most effective manager of the city.”
Mr. Bloomberg supported Mr. Adams, endorsing him in September 2021 during the last mayoral race and giving him advice as he prepared to take office. But Mr. Adams’s first term has been marked by controversy and scandals, leading the mayor to abandon the Democratic primary to run instead as an independent in the general election in November.
Mr. Cuomo said in a statement that he was “deeply honored” by Mr. Bloomberg’s endorsement, calling him “New York City’s pre-eminent statesman.”
“Under his steady hand and with his strong management, New York City was the best-run city in the country, and his leadership has been sorely missed every day since,” he said.