Incumbent New York Gov. Andrew Cuomo defeated his challenger, actor and activist Cynthia Nixon, by 30 percentage points, in the state’s Democratic gubernatorial primary on Thursday after a heated primary race. But most members of the state’s Independent Democratic Conference (IDC)—a group of state senators who campaigned as Democrats but caucused with Republicans, allowing the GOP to control the state senate despite not having a majority—lost their seats.

Six members of the now-defunct group were defeated by their primary challengers. Cuomo’s critics claimed he simultaneously worked to keep the IDC state senators in power and used the divided legislature as a mask for his own centrism.

Now, all but two of the former IDC senators are out, including the group’s leader state Sen. Jeff Klein, who was considered one of the most powerful men in Albany. He was ousted by first-time candidate Alessandra Biaggi. In Queens, state Sens. Tony Avella and Jose Peralta were defeated by John Liu and Jessica Ramos; Brooklyn Senator Jesse Hamilton was toppled by challenger Zellnor Myrie; Manhattan’s Marisol Alcántara lost to Robert Jackson; and in Syracuse, David Valesky lost to Rachel May.

Former IDC members weren’t the only ones who faced primary losses. In Brooklyn, eight-term state senator Martin Dilan, who has long been considered a friend to real estate, was defeated by Julia Salazar, a controversial democratic socialist whose platform included tenants’ rights, Medicare for All, and the decriminalization of sex work.

Susan Kang, a spokesperson for the group No IDC NY, told Rewire.News that Thursday night’s victories were the result of a mix of grassroots organizing and political savvy. “Almost all of them are first-time candidates. Many of them are very, very young, and they bring youthful energy to the [state] senate,” Kang said of the victors. “They came in on a mandate of progressive reforms, like rent protection, single-payer health care, the DREAM Act, [and] protection for reproductive health.”

Kang said some of this energy is a reaction to the 2016 presidential election. “Since Trump’s election, there has been a grassroots resistance. In most states, that’s turning red districts blue. But in New York, we realized that the problem wasn’t Republican-led districts—it was bad Democrats,” said Kang.

Javier Valdés, the co-executive director of the immigrants’ rights group Make the Road Action, said the primary was an opportunity to move the Democratic Party to the left. “I think we were able to show Democrats what it is we expect of people when we elect [them] to the state senate,” Valdés told Rewire.News.

It’s likely that Biaggi and other down-ballot candidates were boosted by the presence of Nixon, attorney general candidate Zephyr Teachout, and lieutenant governor candidate Jumaane Williams’ more high-profile campaigns, despite all of them losing their races. Just 574,350 voters showed up to the polls in the 2014 Democratic governor primary, compared to more than 1.4 million this year, even as registered voters across the state were turned away at the polls.

“In order for us to be able to have the victories that we had in challenging the IDC members, we had to challenge the top of the ticket and call into question the way Albany works,” said Valdés. And even in cases where leftist insurgents didn’t win, Valdés said, they managed to challenge their opponents’ progressive bonafides.

“In what we call ‘the Cynthia Effect,’ we were able to push certain policies to the left,” Valdés said. “It gave [an] opening for us to be able to talk about issues that impact communities of color in a big way.”

Those issues include banning plastic bags, legalizing marijuana for recreational use, and restoring voting rights to formerly incarcerated people—policies Cuomo either actively opposed or claimed he was powerless to enact until Nixon came along. It’s clear that Cuomo, who poured more than $25 million into his campaign and changed his mind on several key issues, took his challenger seriously.

While Cuomo did change course on some issues, some of his policy proposals still stopped short of Nixon’s. At the lone gubernatorial debate, Cuomo said he disagreed with the idea that tax revenue from marijuana—which he called a “gateway drug” as recently as last year—should go to “reparations,” a reference to Nixon’s proposal to reinvest those funds into Black and brown communities affected by the War on Drugs.

But it remains unclear how much of Cuomo’s leftward turn is just for show.

Cuomo’s critics have also noted that the governor reportedly threatened to defund unions and community groups who endorsed Nixon, including Citizen Action of New York, New York Communities for Change, and Make the Road New York. Despite these threats—and Nixon’s loss—Valdés told Rewire.News that backing progressive insurgents was the right move.

“We were very aware of that threat, but in having conversations with our membership, it became very clear that after the Trump election, we can’t continue to make decisions out of fear,” Valdés said. “Albany has not worked for us over the past eight years. We need to take a stand, to make Albany work for us, and this allowed that.”

Nixon said as much during her concession speech, where she characterized her loss as an overall win for the people of New York.

“The Democratic establishment thinks that primaries hurt our party. Well, we have proved them wrong,” said Nixon. “Primaries force politicians to respond not just to their corporate donors on top, but to the grassroots energy pushing up from the bottom. And because of what we did in this campaign, the Democratic Party in New York is stronger, and it’s more focused, and it’s more progressive than when we started.”

Cuomo will face Republican Marcus Molinaro in November’s general election.

CORRECTION: This piece has been updated to correctly identify Javier Valdés’ organizational affliation.