Socialist Surge: Mamdani flexes growing political muscle as he takes on Dem establishment

One year after sending political shock waves across the country with his New York City Democratic primary victory en route to winning election as mayor of the nation's most populous city, Zohran Mamdani is testing the limits of political power as he takes on the party establishment.

The 34-year-old democratic socialist mayor is teaming up with longtime progressive champion and two-time Democratic presidential nominee runner-up Sen. Bernie Sanders, I-Vt., at a get-out-the-vote rally in the New York City borough of Brooklyn on Thursday, less than one week before crucial primary elections.

Mamdani and Sanders are aiming to boost a slate of candidates backed by the mayor, including two who are running against Democratic congressional incumbents, as part of their bid to mold a more progressive party.

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The left-wing candidates endorsed by Mamdani include political organizer Darializa Avila Chevalier, who is primary challenging Rep. Adriano Espaillat, the Congressional Hispanic Caucus chair, in New York’s 13th U.S. House District, which covers the northern third of Manhattan and a sliver of the Bronx. Espaillat is supported by a slew of party leaders, including New York Gov. Kathy Hochul.

The mayor is also backing former New York City Comptroller Brad Lander, who ran against Mamdani last year in the crowded primary field but became one of his biggest backers. Lander is challenging incumbent Democratic Rep. Dan Goldman in the 10th Congressional District, which includes lower Manhattan and parts of Brooklyn. Goldman's supporters include former House Speaker Nancy Pelosi.

And in New York’s 7th, which covers parts of Brooklyn and Queens, Mamdani's endorsed socialist state Assembly Member Claire Valdez, who is battling Brooklyn Borough President Antonio Reynoso, who is backed by retiring Rep. Nydia Velazquez, D.N.Y.

The outcomes of the races Mamdani weighed-in on will put to test whether his popularity among New York Democrats translates to coattails in elections.

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"This is the team. This is our year. It’s up to all of us to get them over the finish line," Mamdani emphasized in a social media post spotlighting Thursday's rally.

The socialist has been a darling of the far-left for a year and a half. But six months into his tenure as New York City mayor, he can also count former critics within the Democratic Party, including Hochul, as allies. And he's even earned praise from President Donald Trump.

Trump last year repeatedly claimed Mamdani was a "communist lunatic," but during an Oval Office meeting in November that grabbed tons of national attention, the president lauded the then-mayor-elect as a "very rational person" who would do a "really good job."

"It's crystal clear that Mamdani understands power and how to leverage it," longtime Democratic strategist Joe Caiazzo told Fox News Digital.

"He remains incredibly popular and it appears he also understands that may not always be the case. That's why I think you see him flexing his political muscle now. It's smart politics," added Caiazzo, a veteran of the 2016 and 2020 Sanders presidential campaigns.

The candidates Mamdani's backing, including some running for state legislative offices, are mostly showcasing the mayor's platform of focusing on affordability in a city with one of the nation's highest costs of living.

Sanders, a New York City native who last year appeared at rallies on Mamdani's behalf and swore in the mayor at his January inauguration, highlighted on social media, "Now more than ever, we need leaders in Congress who understand firsthand the struggles working people face."

Mamdani's support for the trio of congressional candidates, along with Thursday's rally with Sanders, gives Republicans, who have long cast the mayor as a radical, more ammunition to use him as a cudgel as they work to hold their razor-thin House majority in this year's midterm elections.

"Zohran Mamdani’s socialist brand is as toxic as it comes," National Republican Congressional Committee (NRCC) National Press Secretary Mike Marinella told Fox News Digital.

"And during a time when Democrats don’t have a leader or a message, he’s exactly the kind of bogeyman we can use against Democrats to truly show who is leading their party and the crazy policies they all support."

Fox News' Jessica Sonkin contributed to this report