A day after the final debate in the Democratic primary race for New York City mayor, two leading contenders cross-endorsed each other. Comptroller Brad Lander and Queens Assemblyman Zohran Mamdani made the announcement Friday morning. 

The move is not particularly surprising. The two say their joint commitment is an effort to unite against former Gov. Andrew Cuomo, who, since he entered the mayor's race, has consistently led nearly every single poll. 

"Andrew Cuomo's campaign is a house of cards. The two strongest progressive campaigns can topple him, and that's exactly what we're going to do," Mamdani said. 

Mamdani has emerged as a serious challenger, placing second in most of those same polls, with Lander at number three. They think they can topple him if they join forces. 

Under the city's ranked choice voting, each wants voters to rank them first, the other second, and Cuomo not at all. They said if candidates did that in the last election - cross-endorsed - it would have prevented Eric Adams from becoming mayor. 

"Four years ago, we wound up with one of the worst mayors in our history, largely because the two top alternatives in the race did not come together and join forces to cross-endorse each other. We can't afford to make that mistake again. I'm proud to cross-endorse Zohran, because of his strong commitment to a more affordable New York, and to stop the corrupt, morally bankrupt, unacceptable Andrew Cuomo from becoming mayor of a city he doesn't even like," Lander said.

"No surprise here"

Cuomo's camp tried to downplay the development, saying the two hard left candidates are very similar.

"No surprise here — the two have been attached at the hip for months, but it won't move the needle. The public is clamoring for leadership to take real action to make the city safer and more affordable and to protect New Yorkers from Trump. They know Andrew Cuomo is the only one with the experience and the record to get the city back on the right track," a Cuomo spokesperson said. 

"I am proud to rank our principled and progressive comptroller number two on my ballot, because we are both fighting for a city every New Yorker can afford," Mamdani said. 

Political experts think Cuomo should take the threat seriously. 

"This is a crucial moment in the campaign for Governor Cuomo," said J.C. Polanco, assistant professor at the University of Mount Saint Vincent. 

Polanco said Cuomo should highlight the weaknesses of Mamdani and Lander, and he might want to form a coalition of his own with former Comptroller Scott Stringer and City Council Speaker Adrienne Adams. 

"Governor Cuomo, you've got to keep focusing on the experience factor. That is your saving grace. And be sure to reach out to Comptroller Stringer and Speaker Adams, you share natural voters that will support you as a number two. This is a time to make friends, and this is a time to harp on the weakness of the guy who's trailing behind you right now," Polanco said. 

Lander's campaign got a boost Thursday when the majority of a panel put together by the New York Times said he was their top choice for mayor. Cuomo recently got a surprise endorsement from former Mayor Michael Bloomberg, and Mamdani was recently endorsed by Rep. Alexandria Ocasio-Cortez. 

Candidates spar during NYC mayor debate

During Thursday's debate, Mamdani directed a question at Cuomo. 

"Andrew Cuomo, you have received millions of dollars in funding from the very billionaires who put Donald Trump back into office. Will you now look at the camera and tell your Super PAC to return those millions of dollars?" Mamdani said.

"I know you don't understand the law, but it would be illegal for me to direct an independent expenditure committee," Cuomo said.

Cuomo took issue with Mamdani's position on Israel. Mamdani has called the war in Gaza a genocide, and won't say Israel should exist as a Jewish state. 

"I'm not Mr. Mamdani. I'm not antisemitic. I'm not divisive. I didn't say I would boycott Israel," Cuomo said. "We should be selling unity, not the division that this man is spreading."

Lander took aim at the sexual harassment allegations that led to Cuomo's departure from office. 

"Everybody here knows that you sexually harassed women," Lander said.

"Those are just boldfaced lies, and you know it," Cuomo said.

Early voting in the primary begins Saturday.   

• Andrew Cuomo