NEW YORK — Standing on the podium, surrounded by Democratic elected officials who had supported her first-ever candidacy, Tiffany Cabán gave a primary night victory speech Tuesday that seemed unlikely a few months ago, and outright impossible a few years back.

She was a rank outsider challenging more experienced candidates in the primary race for Queens district attorney and did not have the backing of the borough’s powerful Democratic apparatus. That honor went to Melinda Katz, the Queens borough president.

Yet Cabán, a 31-year-old public defender, overcame the institutional disadvantages, a performance that was the culmination of a progressive wave in New York that began three years ago and took flight last year with Alexandria Ocasio-Cortez’s shocking primary win over Rep. Joseph Crowley, one of the most powerful Democratic legislators in the country.

But Cabán’s performance — in a borough of 2.3 million people — may in some measure be more of a turning point for the progressive movement in New York than even Ocasio-Cortez’s victory, which she accomplished in a singular congressional district.

“It shows that there’s a huge movement,” said Rebecca Katz, a Democratic strategist. “It shows this is bigger than any one person.”

The results are not yet official: With 99% of precincts reporting, Cabán held an almost 1,100-vote lead over Katz, with 6,337 uncounted paper ballots remaining, according to the New York City Board of Elections. That includes 3,556 Democratic absentee ballots and 2,781 affidavits, a number that could include Republican votes. That total may grow until the paper ballot count takes place July 3.

Katz has not conceded, but Cabán’s campaign believes her lead will be hard to overcome because they presume the absentee ballots will be divided among the seven candidates.

“You don’t need fancy consultants, you don’t need a million dollars in the bank, you don’t need to wait your turn with a machine,” Cabán said Wednesday morning. “You just need a vision and a true commitment to the people that you want to serve.”

If she wins, it will be because she promised to push progressive criminal justice reform in a working-class borough that had stuck to its law-and-order past, even as changes designed to end mass incarceration swept across the country.

In the world of criminal justice, Cabán’s performance was seen as part of a continuum of progressive prosecutors around the country working to end mass incarceration. Larry Krasner, the Philadelphia district attorney, and Rachael Rollins, the prosecutor in Boston, both endorsed Cabán and visited Queens to campaign for her.

And many expect the reverberations from the Queens district attorney’s race to seep into Albany and the 2021 race for New York City mayor. Scott Stringer, the comptroller of New York City, also endorsed Cabán.

“I never embraced this notion that 2021 will be a traditional campaign,” said Stringer, who has said he will run for mayor. “If you are going to get elected in this town you have to run a progressive campaign.”

The roots of the movement can be traced to the 2016 presidential primary in New York, when Bernie Sanders won 42% of the Democratic vote in the state against the hometown favorite, Hillary Clinton.

Basil Smikle, the executive director of the state Democratic Party during that primary, said he noticed then how the left flank of the party was becoming far better at mobilizing and organizing voters around issues that once seemed too liberal for the party’s base.

“The response to me was more of an open question about how strong they actually were among the electorate,” said Smikle, now a lecturer on politics and public policy at the City University of New York.

Two years later, the seismic intraparty political shifts began. First came Ocasio-Cortez’s victory over Crowley; a few months later, most members of the Independent Democratic Conference, a group of Democratic state senators who worked with Republicans, were swept from office.

That was soon followed by Amazon rescinding its decision to build a campus in Long Island City after progressive activists fought against a plan to provide the company with $3 billion in government incentives.

State Sen. Michael Gianaris was one of the leaders of the opposition to Amazon’s plans. He also endorsed Cabán. “Progressive victories one after another cannot be dismissed as isolated incidents,” he said, adding that the machine “is best advised to come out of denial.”

One of the more notable factors in the race was how it drew national attention: Ocasio-Cortez and Sanders, who both identify as Democratic Socialists, endorsed Cabán, along with Sanders’ fellow Democratic presidential candidate, Elizabeth Warren.

The endorsements helped Cabán make up what had been a sizable fundraising deficit, with many small donations coming from outside New York state.

Cabán thanked the Democratic Socialists of America and the Working Families party on stage Tuesday night, saying that they were the “engine behind this campaign” and that she would not have won without them.

Her support from voters clearly came from western Queens, in some of the same districts that supported Ocasio-Cortez. But she garnered enough support in other areas where she was not expected to do as well, resisting the label of being “just a candidate of gentrifying areas of Queens,” said Steven Romalewski, who directs the mapping service at the Center for Urban Research at the City University of New York’s Graduate Center.

But in a low turnout election — just over 11% of registered Queens Democrats turned out to vote Tuesday — “you have to be careful in making assumptions about the mood of the electorate,” Romalewski added. “Voters are fickle and different people may be voting next time.”

It remains to be seen if the progressive movement will force state lawmakers to tilt even further left than it had this year, when the state Legislature carried out one of the most progressive-oriented agendas in its history.

Bill Lipton, the New York director of the Working Families Party, said he expected there to be “big pushes to tax the wealthy, to fully fund our schools and universities, pass public financing, to reduce the role of big money in elections, marijuana legalization and a continued push for the Green New Deal.”

Gov. Andrew Cuomo seemed to discount any notion of a larger message in Cabán’s performance, attributing it to low turnout.

“If there is low turnout then you can always be victim to a motivated minority,” he said. “It’s always been that way, it always will be.”

But those closer to the primary race said that it was clear that the traditional way of doing politics in New York had changed.

“When we confronted the machine we found a paper tiger,” said Jose Cabrera, 36, a former chairman of the Queens branch of the Democratic Socialists of America, and a lead canvasser on Cabán’s campaign. “They are not as equipped as they would like you to believe.

“We’ve shown we can elect Alexandria Ocasio-Cortez to Congress, we can kick Amazon out of Long Island City and we can elect Tiffany Cabán as district attorney,” Cabrera added. “That’s just in a year.”

This article originally appeared in The New York Times.