He Nearly Ended Cuomo’s Career. Now He Says His Ex-Rival Should Be Mayor.

Former Gov. Andrew M. Cuomo may not yet have entered the race for mayor of New York City, but his campaign in waiting received its most significant endorsement on Saturday from H. Carl McCall, a Black elder statesman who was once Mr. Cuomo’s best-known rival.

In an open letter, Mr. McCall did not mention the current officeholder, Mayor Eric Adams, by name. But he said that a head-spinning series of events surrounding the Justice Department’s move to drop federal corruption charges against Mr. Adams had called into question his independence from President Trump and necessitated new leadership.

“New York cannot be represented by someone whose loyalty to the city is compromised,” Mr. McCall wrote.

“I have never publicly urged a candidate to run for office. But I have never before felt it so necessary to use my voice,” he continued. “For these reasons, I urge Gov. Andrew Cuomo to run for mayor of the City of New York, and I offer my full support.”

The letter came as Mr. Cuomo, who resigned his governorship in scandal in 2021, is taking increasingly decisive steps toward launching a comeback campaign for mayor in the coming weeks.

And it was the latest indication that the once unshakable bond between the city’s second Black mayor and its Black political establishment may be crumbling after the prosecutor overseeing the mayor’s case charged that he had agreed to a quid pro quo with Trump administration officials. Andrea Stewart-Cousins, the State Senate majority leader, joined the chorus of Black leaders calling for his resignation later Saturday.

Mr. Adams is not ready to give in without a fight. A campaign representative for the mayor declined to comment on the letter, but Mr. Adams spent Saturday working the phones to try to regain his footing, reassure allies and impede Mr. Cuomo’s progress.

Former Gov. David A. Paterson, the state’s first Black governor, said that Mr. Adams had told him in a lengthy phone call that he was “all in” on the race and “hopes Andrew is ready for a tough campaign because he is.” He also took a dig at Mr. McCall, 89, who endorsed him in his 2021 race.

“He basically suggested that someone wrote the paper and McCall signed it,” Mr. Paterson said, referring to the letter. “He said, ‘he’s probably on a respirator.’”

Mr. McCall denied Mr. Cuomo had written the letter, though it did have all the signs of being a coordinated effort with the former governor, who has been careful not to directly comment on Mr. Adams’s predicament while privately moving to capitalize on it.

Just minutes after Mr. McCall’s letter was circulated, Mr. Cuomo put out his own lengthy statement thanking his former opponent “for his faith in me and for his advice, trust and confidence.” It did not directly address the mayor’s race.

As Mr. Cuomo knows well, few endorsements could be more valuable symbolically or practically as he tries to carefully peel away Mr. Adams’s Black base of support, a crucial constituency for any New York City mayoral run, without prompting a backlash.

Mr. McCall, a former New York State comptroller, was Mr. Cuomo’s first political opponent in an ill-fated 2002 bid for governor that has lingered for decades in the memory of some Black New Yorkers.

The race ended in humiliation for Mr. Cuomo, and his tactics infuriated Black leaders who felt that the brash young political scion had harmed Mr. McCall’s chances of becoming the state’s first African American governor.

Mr. Cuomo spent decades carefully rebuilding relationships with Black Democratic leaders. And as he has contemplated a run against Mr. Adams, allies of the current mayor and of Mr. Cuomo alike have pointed to the McCall-Cuomo contest as a cautionary tale.

Mr. Adams, who maintains that he is innocent of all charges and has not entered into any deal with Mr. Trump, has already begun leveraging race in the contest. An anti-Cuomo group also began airing ads charging that Mr. Cuomo “didn’t care much about Black New Yorkers until he got into trouble.”

On Saturday, Mr. McCall, who was later appointed by Mr. Cuomo to lead the board of the State University of New York, brushed aside those concerns.

“Some might be surprised that I am supporting Andrew so strongly and so early,” he wrote in the letter. “But despite how it is sometimes framed in the press, we were never political adversaries: 20 years ago, we were competing candidates who shared then and share now the same core values of what is right and wrong and sought to make New York a better place.”

Many Black New Yorkers do not share that view. “I will never forget the McCall-Cuomo race. Never,” said Bertha Lewis, the president of the Black Institute, a research and advocacy group. “It was nasty, it was dirty and it was wholly uncalled-for.”

Ms. Lewis recently published an opinion essay accusing Mr. Cuomo of “a longstanding pattern of divisive politics towards the Black community” and is helping run an anti-Cuomo group.

Notably, Mr. McCall’s letter did not grapple with the scandals that precipitated Mr. Cuomo’s resignation. Mr. Cuomo was facing a damning investigative report by the New York attorney general’s office that concluded that he had sexually harassed multiple state employees, charges he has denied. The governor was also under scrutiny for how he had handled Covid cases in nursing homes.

Mr. Cuomo, 67, has still not set a timeline to enter the race. He has until April 3 to collect the necessary petitions to get on the primary ballot, and will need to raise money well before that. But after weeks of remaining out of public view, the Democrat has begun to raise his profile.

Mr. Cuomo has met privately in recent weeks with key city stakeholders, including Kathryn Wylde, president of the influential Partnership for New York City; and Representative Adriano Espaillat, the chairman of the Congressional Hispanic Caucus and a supporter of Mr. Adams in 2021.

On Friday, Mr. Cuomo posted an upbeat campaign-style video with footage of him embracing Black and Latino seniors gathered for a Valentine’s Day event hosted by Assemblyman Eddie Gibbs. (Mr. Gibbs said he was undecided on who to support in the mayor’s race.)

“I missed you,” Mr. Cuomo, looking trimmer and grayer than when he left the governor’s mansion, declared to applause in the video.

He again did not mention running for mayor, but he presented himself as a figure ready to protect New Yorkers from crime and from Mr. Trump: “We know how to make this city work and make this state safe for everyone and that’s exactly what we’re going to do.”

Around the same time, the Staten Island Democratic Party endorsed Mr. Cuomo and urged him to enter the race. “We believe Andrew Cuomo is the only proven leader with the track record of results and the resolve to both navigate attacks from Washington and properly address the issues of corruption and deteriorating quality of life that our city faces today.”

The group’s chairwoman declined to say whether or not she had spoken with the former governor’s team about his potential candidacy.

A tight-knit group of longtime Cuomo advisers have been making preparations to finance a campaign. In addition to the likely creation of a super PAC outside the campaign, Mr. Cuomo’s longtime fund-raiser, Jennifer Bayer Michaels, has begun securing commitments from major donors to host events directly for the former governor should he enter the race, according to two people familiar with the planning who were not authorized to discuss it publicly.

Other prominent Black Democrats also appear to be reconsidering their positions on the race.

The Rev. Al Sharpton and Representative Hakeem Jeffries, the top House Democrat, both publicly said this week that they feared the mayor had let himself be put “on a short leash” by Mr. Trump. Mr. Sharpton and others have been speaking regularly with Mr. Cuomo, though he has not publicly supported him.

Mr. Paterson, for his part, said he was not ready to urge Mr. Adams to step aside. Still, he said that whether the mayor had knowingly entered into a corrupt bargain with the Justice Department or not, “it definitely creates a perception that there is some kind of understanding there” that would harm him politically.

Mr. Paterson said that Mr. Cuomo, whom Mr. Paterson has accused of trying to shove him and Black rivals aside in the past, needed to assess how deep Mr. Adams’s Black support remained.

“The polls show that he is pretty much dropping everywhere in all communities,” he said of Mr. Adams. “So does that open the door wide enough for Andrew to consider running? I think it does.”

Mr. Paterson also spoke with Mr. Cuomo this week, he said, and offered him a word of advice about his low profile.

“I suggested to him that after the dismissal” Mr. Paterson said, referring to the mayor’s charges, “this would be a good time to stir it up a little more.”

Jeffery C. Mays and Dana Rubinstein contributed reporting.