Cuomo, now running as an independent, continued to try to cast Mamdani’s agenda as too extreme, saying he lacks the experience to lead America’s biggest city. Mamdani, a self-described democratic socialist, countered with attacks on the former governor’s response to the COVID-19 pandemic and sexual harassment allegations that Cuomo denies.

But after two hours that touched on how the next mayor would deal with President Donald Trump, quality of life issues and affordability, it was unclear whether anyone did enough to move the needle.

For Cuomo the stakes of the face-off were especially high. The debate was one of his last chances to try to convince voters that going with Mamdani, who already defeated the once-powerful governor in the primary this summer, would be a mistake. The race is also Cuomo’s attempt at a political comeback after he resigned four years ago following the sexual harassment allegations.

Mamdani, who spent much of the debate smiling as he tried to maintain the hopeful, charming persona that has characterized his campaign, pushed his affordability agenda and sought to portray himself as a pragmatic liberal rather than a radical ideologue.

The race has catapulted him to national political stardom, with Republicans, including Trump, trying to turn him into the face of the Democratic Party by highlighting his most controversial past comments and positions and casting him as dangerous, a communist and an antisemite.

Meanwhile Sliwa, a Republican and the colorful creator of the Guardian Angels crime patrol group, tried to vault his underdog campaign to the fore amid calls for him to drop out. Though he could have helped Cuomo by ganging up on Mamdani, he instead spent much of his time undercutting the former governor.

Incumbent Mayor Eric Adams, a Democrat, suspended his reelection campaign late last month after being deeply wounded by a now-dismissed federal corruption case and his relationship with the Trump administration.

Here are some key takeaways from tonight’s debate:

Mamdani on defense

Mamdani came under attack straight out the gate, as Cuomo highlighted the 33-year-old’s relative lack of job experience and painted his agenda as unrealistic and unachievable.

Cuomo, stressing his own lengthy resume, said being mayor “is no job for on-the-job training”

“This is not a job for a first timer,” he said, while trying to to cast Mamdani as “Bill de Blasio light,” a reference to the unpopular former mayor.

Mamdani hit back at Cuomo’s integrity and decision-making during the pandemic and repeatedly raised the sexual harassment investigation and legal bills related to his defense.

“What I don’t have in experience, I make up for in integrity. What you don’t have in integrity, you can never make up for with experience,” he charged.

Cuomo also sought to cast himself as the only true Democrat onstage, despite the fact that he is not running on the Democratic Party line.

Mamdani’s brand of economic populism and laser focus on lowering costs in the astronomically expensive city has generated buzz and excitement. At the same time, the state assemblyman’s calls to raise taxes on wealthy people and intense criticisms of the Israel’s military actions in Gaza have unnerved some centrists and conservatives, as well as many Jewish New Yorkers.

Mamdani pressed on past Israel comments

During an appearance on Fox News Channel this week, Mamdani sidestepped a question about whether Hamas should lay down arms as part of a fragile truce that has paused the two-year Israel-Hamas war.

On Thursday he did not equivocate, saying, “Of course I believe that they should lay down their arms.”

The comment came as Cuomo again highlighted Mamdani’s past reluctance to condemn the use of the phrase “Globalize the intifada,” which is seen by many Jews as a call to violence.

Since the primary Mamdani has said he does not use the phrase and would discourage people from saying it.

But Sliwa said that wasn’t enough. “Jews don’t trust that you are going to be there for them when they are the victims of antisemitic attacks,” he charged.

Mamdani, meanwhile, accused Cuomo of failing to represent the city’s Muslim community, claiming that it took losing to a Muslim candidate for Cuomo to step inside a mosque.

“It took me to get you to even see Muslims as part of this city,” Mamdani said.

Mamdani’s walk-back comes as he has tried to distance himself from several of his more contentious past statements, such as calling the New York Police Department “racist” and “a major threat to public safety.”

During his Fox appearance, he publicly apologized for his language after doing so behind closed doors.

“I am not running to defund the police. I am running to actually work with the police to deliver public safety,” he said Thursday.

Trump front and center

The president, who has threatened to arrest Mamdani, to deport him and even to take over the city if he wins, was invoked early and often.

Pressed on how they would handle Trump, Mamdani — who walked to the debate venue at 30 Rockefeller Plaza from Trump Tower, accompanied by a brass band — said he would stand up to the president while also being willing to work with him on lowering costs and affordability.

“What New Yorkers need is a mayor who can stand up to Donald Trump and actually deliver,” he said.

Cuomo warned that if Mamdani wins, “It will be Mayor Trump.”

“I’d like to work with you. I think we could do good things together. But No. 1, I will fight you every step of the way if you try to hurt New York,” Cuomo pledged.

Sliwa warned that taking too contentious a tone with Trump would end up hurting the city.

“If you try to get tough with Trump,” he said, “New Yorkers will suffer.”

Sliwa tries to stand out

The underdog found himself caught in the middle — literally and figuratively — with the Republican’s lectern positioned between his two opponents as they lobbed attacks at one another.

At one point Sliwa complained that he was not getting enough speaking time, saying, “I am being marginalized out of this.”

But he often attacked Cuomo aggressively, including after the former governor stressed his willingness to take on Trump.

“The president is going to back down to you?” Sliwa said. “You think you’re the toughest guy alive, but let me tell you something, you lost your own primary, rejected by your own Democratic Party.”

A second and final debate is scheduled for next week.