Brad Lander, the New York City comptroller and self-described “tough nerd,” knows that for him to win the race for mayor of New York City, Andrew M. Cuomo must fall.

To make that more likely, Mr. Lander decided that his campaign strategy needed an overhaul. He would no longer focus his ire on the increasingly inconsequential mayor of New York City, Eric Adams, and his apparent alliance with the Trump administration.

Instead, Mr. Lander, the Park Slope father with the University of Chicago degree, would use his distinctive voice — a singsong lilt that his critics find grating — to try to take down Mr. Cuomo, the former governor leading in the polls.

During a Passover week meal of latkes and matzo ball soup at a restaurant on Montague Street in Brooklyn, Mr. Lander unspooled his indictment of Mr. Cuomo, allegation by allegation.

“I know he looks like a good leader, but actually, you know, he’s just a corrupt chaos agent with an abusive personality that has shown through in every position he’s been in, and that’s dangerous for New York City,” Mr. Lander said, stopping only to spread sour cream and apple sauce on his potato pancake, or to sip from his French 75, a cocktail he likes because it is fizzy.

New Yorkers, he said, deserved a stark alternative: “I am a decent person. Let’s just start there.”

In eight weeks, Democratic primary voters will choose a candidate for mayor, with the victor promptly becoming the favorite to win the November general election in a city where Democrats outnumber Republicans six to one.

What kind of person New Yorkers want as their mayor is the elemental question of this and any mayor’s race. Do they want someone who projects a muscle-car style of masculinity, like the former governor, who resigned in disgrace in 2021 after an investigation found he had sexually harassed 11 women? (Mr. Cuomo has denied wrongdoing.)

Would they rather a female politician adept at projecting an even-tempered self-confidence, like the City Council speaker, Adrienne Adams? Would they prefer a charismatic democratic socialist and son of a movie director from Queens with an age-appropriate aptitude for social media, like Assemblyman Zohran Mamdani, who is now polling in second place?

Or would they like Mr. Lander, an earnest-seeming policy wonk who read Antigone in the original Greek; a former member of the Democratic Socialists of America who in 2020 said he still considered himself a member, but whose spokeswoman now says hasn’t attended a D.S.A. meeting in decades; a critic of the city-backed financing of the Hudson Yards development on Manhattan’s West Side who has since come around; a reform Jew who considered becoming a rabbi, and who is also an anti-occupation Netanyahu critic who cursed Mr. Cuomo in Yiddish as he accused him of wielding antisemitism as a political weapon?

At the moment, it appears that New York City voters are looking elsewhere. Mr. Lander is polling at 6 percent among registered Democratic voters, well behind Mr. Mamdani, a liberal upstart who has energized much of Mr. Lander’s presumptive base. Twenty percent of voters remain undecided. Mayor Adams has opted out of the Democratic primary and will run as an independent in November instead.

Lander partisans note that it is early. At this point in 2021, Andrew Yang was still leading the polls, Mr. Adams was in second place, and Maya Wiley, a civil rights lawyer, and Kathryn Garcia, the former sanitation commissioner, were polling at 7 and 4 percent, according to a Spectrum News NY1/Ipsos poll from the time.

That June, Ms. Garcia lost to Mr. Adams by just 7,000 votes, Ms. Wiley finished third, and Mr. Yang finished fourth. And Mr. Lander won the Democratic primary for comptroller.

“What I did last time to win was build a coalition that had the Maya Wiley voters, like people that have a more progressive vision of a city that can deliver on affordability, and Kathryn Garcia voters, who just want a good manager who loves New York City,” Mr. Lander said.

“And I believe that coalition still exists and can be a majority of the Democratic primary electorate.”

But first, Mr. Lander said, Mr. Cuomo has to be “knocked down.”

To that end, Mr. Lander has bombarded the press with anti-Cuomo messaging, hoping that something, anything, will stick.

“Lander Demands Cuomo Release His Tax Returns After History of Shady Business and Lies About His Income,” read one news release. “In Addition to Shady Crypto Client, Who Else Has Cuomo Been Paid to Advise Since Resigning as Governor?” read another.

Mr. Lander’s first real political encounter with Mr. Cuomo happened in 2017, when Mr. Lander was the city councilman representing Park Slope, Brooklyn, and Mr. Cuomo was still governor.

Mr. Cuomo effectively killed a New York City law imposing a 5-cent fee on plastic bags that Mr. Lander had sponsored, acting right before it was set to begin. “Plastic bags won,” Mr. Lander said at the time.

Four years after Mr. Lander’s bill passed the City Council, a plastic bag ban signed by Mr. Cuomo went into effect.

“We call that 40 billion plastic bags later,” Mr. Lander said.

More damning, Mr. Lander argues, were the Cuomo administration’s choices during the height of the Covid pandemic, when it directed nursing homes to accept infected patients, and then failed to publicly account for the deaths of more than 4,000 nursing home residents, according to an audit by the state comptroller, Thomas P. DiNapoli.

Mr. Lander has also tried to highlight the estimated $61 million New York has spent on legal representation related to issues surrounding Mr. Cuomo’s tenure.

“In every relationship, he views it as like, how could I manipulate this other party to my benefit?” Mr. Lander said. “And I really think that’s how he thinks about New York City.”

And so, inevitably, more than an hour into a pro-migrant, pro-trans-rights, pro-Mr. Lander event at a Unitarian church in Brooklyn Heights, Mr. Lander turned to Mr. Cuomo.

He pinned Mr. Cuomo’s polling status on “name recognition in a time of Trumpian distraction” and “pandemic memory repression.” He invoked a former Syracuse mayor, Stephanie Miner, who recently described Mr. Cuomo’s kissing her against her will as a power play. He brought up Covid and the $5 million book deal on which Mr. Cuomo used government resources. He noted that Mr. Cuomo’s lawyer had sought the gynecological records of a woman who had accused him of harassment.

“This is an abusive, corrupt person who is running for his own revenge tour,” Mr. Lander said. “He is not looking to solve the problems of New York City, where he hasn’t lived in 25 years.”

Then Mr. Lander asked the room to sing “Happy Birthday” to his 81-year-old mother, whose celebration he was missing while on the campaign trail. The audience happily complied.

In a statement, Esther Jensen, a spokeswoman for Mr. Cuomo, described Mr. Lander’s strategy as “bizarre.”

“New Yorkers aren’t naïve,” she said. “They know Governor Cuomo is the only person in this race with the proven record of accomplishment, and leadership necessary to effectively confront the very serious challenges we face, and take on President Trump, which is why these repeated gutter attacks from Brad Lander, a career politician, with no meaningful record or vision of his own, are not only not working, but backfiring.”

Mr. Lander, the 55-year-old son of a St. Louis lawyer and guidance counselor, met his wife at the University of Chicago and moved to New York City in 1992, so she could attend N.Y.U. law school. He found work running a community development corporation and then the Pratt Center for Community Development, both in Brooklyn.

After Mr. Lander announced he would run for mayor, he began tacking toward the center, renouncing the defund the police movement he had once supported and giving a pro-growth speech at a prominent civic association.

The speech won the respect of Dan Doctoroff, a former deputy mayor under Michael R. Bloomberg and a driving force behind New York City’s economic development. “The most important thing is he’s adopted my vision of the pro-growth cycle,” Mr. Doctoroff said of Mr. Lander.

It was a strategy seemingly predicated on the idea that moderates seeking competent governance would coalesce with left-leaning voters behind Mr. Lander.

He has cast himself as a liberal with managerial chops, and a housing expert who promises to end the mental health crisis on city streets and to build apartments on public golf courses. But the left seems more enamored of Mr. Mamdani these days.

In this city of shifting political loyalties, the pendulum may still swing in unexpected ways.

At this point in 2021, Ms. Garcia, who was running on her managerial competence, was a political afterthought. Then she surged forward, winning the endorsements of The New York Times and The Daily News.

Many voters still “want someone who is going to be a good manager,” said Basil Smikle, a Democratic strategist who formerly led the state party. He added that voters were also looking for someone who could stand up to Mr. Trump.

“Brad Lander has a chance if he can make the case that he can do all of those things,” Mr. Smikle said.