Zo’s red wedding was small, but a bloodbath nonetheless.

Just 7% of active voters supported Mayor Zohran Mamdani’s radical ally Darializa Avila Chevalier over establishment Democrat Rep. Adriano Espaillat in Tuesday’s main event primary, data shows.

The overall low turnout — roughly 17% of active Democratic voters citywide, according to state data — came as Avila Chevalier and two other Mamdani-backed House primary winners captured a mix of high-earning, young, white and black voters, analysts found.

Insiders also credited the Democratic Socialists of America’s formidable field operations for turning out voters who’d back Mamdani’s preferred candidates — setting the stage for a potential party takeover by the DSA.

“This was the red wedding and the victims of the red wedding were the Democrats,” said JC Polanco, a political analyst and professor at the University of Mount Saint Vincent in The Bronx.

“It’s a hostile takeover by the Democratic Socialists of America who have demonstrated that they have the organization to win primaries where there is no voter turnout,” Polanco told The Post Wednesday.

“In some of these districts nobody votes, it’s a very small turnout and the Democratic Socialists of America come in and win. They’ve taken over the party locally.”

Even for ultra-liberal New York City, the wins by Mamdani’s candidates ultimately came from small slivers of the city’s approximately 3 million active Democratic voters, data shows.

Avila Chevalier drew roughly 33,000 votes from 449,000 active voters in the 13th House District covering much of Upper Manhattan, including Harlem, and a swath of the Bronx, preliminary election data shows.

Steve Rattner, an economic analyst, posted on X that election data showed college-educated, non-Hispanic voters were more likely to vote for Avila Chevalier.

“Last night’s big wins for Mamdani-backed candidates were driven by young college grads, often at odds with the party’s traditional working-class & minority base,” he wrote.

The district is predominantly Hispanic and black, with respectively 52% and 23% of residents, according to US Census data. Roughly 28% of residents have a college degree and the typical household income is $52,000 a year.

Avila Chevalier swept white voters — 68% to Espaillat’s 39%, according to VoteHub, nonpartisan political media organization. White residents represent just 15% of the congressional district, the US Census shows.

The community organizer and doctoral candidate also won 55% of the vote in heavily black precincts, compared to her opponent’s 45%, VoteHub found.

Insiders pointed out Espaillat, the first formerly undocumented member of Congress and first Dominican-American to serve, had drawn on the district’s large Hispanic population as a power base over his five terms in office.

But he also had a strained relationship with Harlem’s black establishment. He alienated many of its black voters with his past challenges against longtime Rep. Charles Rangel, said Manhattan Democratic leader and Harlem power broker Keith Wright.

“Espaillat’s support in the black community was very soft,” Wright said. “Democrats voted for change.”

Wright noted his son Jordan Wright, who is not part of the DSA, prevailed in his bid to keep his state Assembly seat in Central Harlem.

“People split the ticket,” he said, noting some Democrats might have backed Avila Chevalier while also voting for his son over DSA rival Conrad Blackburn. 

The 70nd Assembly district — known as “Black Harlem” — saw Avila Chevalier receive 7,707 votes to 5,529 for Espaillat, election data shows.

Espaillat only carried one uptown district — his power base in Washington Heights — but only by 6,868 to 5,719 votes, according to the data.

Like Avila Chevalier, fellow Mamdani-backed DSA diehard Claire Valdez’s win came from an ultimately small group — roughly 38,000 votes out of 456,000 active total voters in the 7th House District, or 8.24% of them, data shows.

Despite her opponent, progressive Brooklyn Borough President Antonio Reynoso, faring well among the Satmar Hasidic community, Valdez outperformed him among white and Hispanic voters — similar to the coalition that propelled Mamdani to Gracie Mansion, VoteHub found.

She also captured higher-income voters in the affluent district that covers part of Brooklyn’s and Queens’ “Commie Corridor,” including Williamsburg, Greenpoint, Astoria and Long Island City. White people account for 37% of residents, followed by 36% Hispanic, 13% Asian and 10% black, according to US Census data.

Former City Comptroller Brad Lander’s blowout victory over Rep. Dan Goldman in the Tenth Congressional District came from massive margins from nearly every demographic group, the VoteHub analysis found.

Lander, as a former City Council member, was long a political fixture in the district’s Brooklyn neighborhoods of Park Slope and Sunset Park in Brooklyn. The seat — which also covers the Financial District and Greenwich Village — is 49% white, with a typical household income of $120,000 and well-educated, according to US Census data.

Beyond the trio’s success at courting different constituencies, the DSA’s ground game shouldn’t be discounted, said Alex Camarda, senior policy adviser at Reinvent Albany, a good government organization.

Traditional Democrats, as well as Republicans, just don’t seem to excite young people or try to bring new voters into their party, Camarda said.

“I think the DSA’s support has come in that they have been successful in inviting people in and volunteering and getting behind their candidates,” he said.

“In the same way people go see certain shows or movies, they do it at the suggestion of their friends, and DSA has really been successful at that and the other political parties have not or they’re not making the effort.”