New York's Democratic primaries show Mamdani's win was no fluke

At polling stations across New York City on Tuesday, an electoral storm was brewing.

Less than seven months after Zohran Mamdani completed his stunning run to defeat former Governor Andrew Cuomo and become the youngest mayor of New York City in a century, a trio of Mamdani backed left-wing congressional candidates accomplished similar feats.

Two of the candidates Mamdani endorsed, New York City Comptroller Brad Lander and community activist Darializa Avila Chevalier, unseated incumbent Democratic congressmen.

One of the defeated, 79-year-old Adriano Espaillat, had served five terms in the House of Representatives and was the leader of the Congressional Hispanic Caucus. The other, Dan Goldman, made his name as the lead lawyer in Trump's first impeachment trial and had the financial support of Aipac, the deep-pocketed pro-Israel lobbying group.

In the third race, state assemblywoman Claire Valdez beat an opponent who had the backing of much of New York City's Democratic establishment.

It was the kind of clean sweep that suggests Mamdani's decisive mayoral victory last year was no fluke. He has assembled a coalition in New York City that is capable of elevating like-minded candidates to office, all of who celebrated Mamdani's backing in their Tuesday night victory parties.

"I want to thank our mayor," Valdez said. "Tonight we have not just won an election, but we have proved that this movement is durable."

The trio of victories were a stark illustration of the divisions in the Democratic Party and sent clear a message to its leaders across the US.

Given that the three newly minted Democratic congressional nominees in New York are virtual locks in the city's November general election, Mamdani's socialist movement – with its focus on populist economic issues like government-funded health insurance, higher taxes on the wealthy and affordable housing - is no longer limited to the confines of America's largest city.

It is spilling out into national politics.

If Democrats succeed in gaining a majority in the House of Representatives in November, there is likely to be a larger, more vocal left-wing contingent among their ranks. That could prove to be a challenge for leaders like Hakeem Jeffries – who represents a portion of New York City in the House of Representatives – as he seeks to unite the factions within his party.

Neither Chevalier nor Valdez have said whether they would support Jeffries if, as expected, he seeks to be speaker in a Democratic-controlled House next year.

At the very least, the anti-incumbent, anti-establishment sentiment among Democratic voters on display on Tuesday has drawn comparisons to the right-wing Tea Party movement that unseated longtime Republican officeholders starting in 2010 and led to a rowdy, and at times uncooperative contingent of conservatives in Congress.

Lander, for his part, sought to dispel what could be growing concerns among Democratic leaders.

"We're joyful about what it looks like to deliver," he said in a television interview on Wednesday. "That is very different energy than what the Tea Party brought. We want to build something, not just break something.

Democrats, however, will have to agree on what to build – and a legislative agenda that can serve as a counterpoint to Trump and the congressional Republicans.

Those Republicans are already eager to paint the New York primary results as an indication that the Democratic Party is swinging dangerously to the left.

"America the beautiful will never be communist country," Trump wrote in a late-night social media post.

"Mayor Mamdani pulled through 3 solid Communists," he wrote later on Wednesday, before going on to complain that the media ignore his own, more impressive endorsement power.

Republicans have already begun amplifying comments on social media by Chevalier, who has called for a world with open borders, no prisons and no police. She has also been sharply critical of Democratic leaders, directing an expletive at former Vice-President Kamala Harris and accused former President Joe Biden of being a rapist.

During her campaign, however, the 32-year-old community organiser disavowed her past comments, made between 2018 and 2022, and said she is a different, more mature person now.

Her victory, however, prompted quick pushback from some Democrats, including former national committee chair Jamie Harriosn.

"If you hate the Democratic Party, then please don't run for our nomination," he wrote on the social media website Bluesky. "Don't use our resources. Don't rely on our volunteers. Don't use our infrastructure. Don't ask Democrats to invest their time, money, and energy in your campaign."

Chevalier's victory, however, is the latest example of Democratic voters showing a willingness to embrace a candidate's message even if it comes with a chequered past.

Two weeks ago, Maine Democrat voters backed Graham Platner as their Senate nominee despite his inflammatory social media posts, Nazi-affiliated tattoo and allegations of menacing behaviour toward romantic partners.

In other races on Tuesday, however, more traditional, centrist Democrats prevailed – suggesting that while voters in places like New York City and Maine may be restive, the national trends are not as clear.

In Utah, Democrats backed former Congressman Ben McAdams for a newly created Democratic-friendly congressional district over more liberal alternatives. And in a Maryland seat outside of Washington DC, Democrats opted for a moderate candidate who endorses continued US support for Israel – a stark a contrast to the pro-Palestinian sentiment among many New York City's victorious candidates.

In November's midterm congressional elections, Democrats will have to win in battleground seats scattered across the nation – including some in the suburbs outside solidly liberal New York City – if they want to secure a majority. And the winners of those races will have politics decidedly different from the three Mamdani-backed socialists.

All this suggests a Democratic party still grappling with its identity and direction heading into November and on into the 2028 presidential campaign – a race that Mamdani, in endorsing the left-wing candidates, has said he hopes to influence.

"The old politics that got us into this crisis is not the politics that's going to get us out of this crisis," he said on Tuesday night, as he bounced between victory parties.

For one night, at least, the old politics – and the Democratic old guard in Washington – has been caught on its heels.

Follow the twists and turns of Trump's second term with North America correspondent Anthony Zurcher's weekly US Politics Unspun newsletter. Readers in the UK can sign up here. Those outside the UK can sign up here.