The race to pick the Democratic nominee for mayor ends Tuesday with primary Election Day — and so far early voting has surged to nearly twice the turnout of four years ago.

In the final weeks, the contest has narrowed into a fight between two men: Andrew M. Cuomo, the 67-year-old former governor who resigned in scandal in 2021, and Zohran Mamdani, a 33-year-old socialist state assemblyman whose government service began that same year. The incumbent, Eric Adams, has seen his popularity collapse since he was investigated and indicted last year for alleged corruption — charges the Trump administration later ordered dismissed. Adams withdrew from the Democratic primary but plans to run later this year as an independent.

“Zohran Mamdani had been in a distant second place for much of this race. He is now in a close, competitive second place. This is a very close election,” said political consultant Trip Yang, who isn’t working for any of the mayoral candidates. “What will determine the race is that, has Zohran Mamdani’s surge leveled off or not?”

The winner will run in the general election — this year, Nov. 4 — but in a city where Democrats outnumber Republicans 7 to 1, winning the Democratic primary is typically akin to winning the mayoralty.

Mamdani is still behind Cuomo, but as the former governor's once-commanding lead has shrunk, millions have been poured into pro-Cuomo super PACs, which are technically unaffiliated with his campaign and can skirt legal limits on traditional candidate contributions such as donation caps, as well as bans on those who do business with the city and corporate contributions.

In recent weeks, New York’s billionaire ex-mayor, Mike Bloomberg, gave a pro-Cuomo super PAC $8.3 million, more than any one candidate is legally allowed to raise if participating in the city's matching funds program, which Mamdani and Cuomo are. The main pro-Cuomo super PAC, called Fix the City, is the best funded super PAC to ever partake in a New York City municipal election.  

Yang noted that pro-Cuomo campaigns have spent millions of dollars attacking Mamdani — in mailers, on billboards, on TV and in newspaper ads.

“Can he continue to surge despite that onslaught?” Yang said.

Cuomo, who has campaigned from the shadows, is running as an experienced hand in government who will steer the city through tumultuous times, stand up to President Donald Trump, build or preserve 500,000 new housing units, hire 5,000 more police officers, remove homeless people from the subways and restrict e-bikes.

Mamdani says he wants to see taxes raised on the richest New Yorkers to fund social programs, make public buses and child care free, freeze rent on regulated apartments, open municipal grocery stores and maintain the current NYPD headcount while supplementing the force with a community safety department. He would use empty storefronts and other vacant spaces in the subway system as drop-in hubs for the mentally ill and homeless.

Earlier this month, at the two mayoral debates of the race, the candidates argued over allegations of corruption, bad COVID-19 policy and sexual harassment against Cuomo; Cuomo's age and Trump-tied, billionaire donors; Mamdani’s youth, relative inexperience and leftist, tax-the-rich agenda; and their respective positions on Israel.

If elected, Cuomo would be the oldest mayor in modern New York City; Mamdani would be among the youngest.

The election is being held by ranked choice voting, in which voters can rank up to five candidates. So even if a voter’s top choice doesn’t win, voters can still help decide who does.

Under ranked choice, a candidate wins by getting over 50% of first-choice picks. If no one hits 50%, counting keeps going in rounds, with the last-place candidate eliminated and the vote of each person who voted for the eliminated candidate going to the highest-ranking remaining candidate left on their ballot, a process that continues until a candidate reaches 50%.

A Marist poll released last week shows Cuomo would win in the seventh round by 10 points, 55% to Mamdani's 45%; just one month earlier, Marist found he was winning in the fifth round with 24 points, 53% to 29%. 

The other candidates — Adrienne Adams, the City Council speaker; Brad Lander, the current city comptroller; Zellnor Myrie, a state senator; Jessica Ramos, also a state senator; Scott Stringer, the former comptroller; Whitney Tilson, a former hedge fund manager; and Michael Blake, a former state assemblyman — are polling in the single digits.

Primary Election Day is forecast to hit 100 degrees, according to National Weather Service meteorologist John Cristantello. Cuomo’s campaign has demanded portable air conditioners be installed in polling sites that lack them, along with bottled water provided, according to his spokesman, Jason Elan. The Board of Elections said portable fans would be brought in and that water will be available — which Elan said in a text message is "wholly insufficient."

On Saturday, the state repealed a part of election law criminalizing the provision by anyone except officials of items of small value at polling sites, ostensibly to induce attendance — including refreshments. That means water now can legally be distributed to those waiting in line to vote.

On Tuesday night, the unofficial winner could be known, but only if a candidate gets at least 50% of first-choice votes. Otherwise, the ranked choice process will be run starting July 1 at noon, the earliest the ranked-choice winner could be known, as in the interim memory sticks from more than 3,000 machines citywide are physically collected, board of elections deputy executive director Vincent M. Ignizio told Newsday Saturday by text.

In 2021, it wasn't until early July that Eric Adams, a former police captain, state lawmaker and borough president, was declared winner, as the ballots were tabulated, ranked choice calculations run, and challenges handled. 

According to a Board of Elections X post, so far this year, 305,896 people voted in the first eight days of early voting, which began June 14, compared with 155,630 in the first eight days of 2021's early voting, the primary election Adams won.

That election demonstrated the limits of opinion polls, what can change in the final weeks, and how voters are the ultimate decision-makers.

A 2021 Marist poll released just before the election showed Adams with an eight-point lead over Kathryn Garcia, a former top official in the de Blasio administration.

When the winner was declared less than a month later, Adams’ victory was by barely a percentage point.