US President Donald Trump has reacted to Democrats winning key races in the first major elections since his return to the White House by blaming the ongoing government shutdown.

“If you read the pollsters, the shutdown was a big negative factor for the Republicans,” Trump said during a breakfast with Senate Republicans on Thursday (AEDT).

Both parties blame each other for the 36-day government shutdown, which caused food stamps (SNAP benefits) to lapse for the first time this month. The shutdown, which shows no signs of being resolved, is already the longest in US history.

Trump also said Republicans had faired poorly because “I wasn’t on the ballot”. He dismissed the blue surge by saying the wins were mainly in Democratic seats.

“Last night, it was not expected to be a victory, it was very Democrat areas. I don’t think it was good for Republicans. I don’t think it was good for anybody. We had an interesting evening and learned a lot,” he said.

A new generation of Democrat leaders swept to power on Wednesday, giving the beleaguered party a long-sought shot of momentum before the 2026 congressional elections.

In New York City, Zohran Mamdani, a 34-year-old democratic socialist, won the mayoral race, capping a meteoric and unlikely rise from an anonymous state lawmaker to one of the US’s most visible Democratic figures.

After becoming the first Muslim to lead New York, Mamdani spoke directly to Trump, saying he had “four words for you”.

“If anyone can show a nation betrayed by Donald Trump how to defeat him, it is the city that gave rise to him,” Mamdani told a raucous crowd of supporters in his victory speech.

“If there is any way to terrify a despot, it is by dismantling the very conditions that allowed him to accumulate power.

“So Donald Trump, since I know you’re watching, I have four words for you: Turn the volume up.”

More than two million New Yorkers cast ballots in the contest, the largest turnout in a mayoral race in more than 50 years, according to the city’s board of elections.

With roughly 90 per cent of the votes counted, Mamdani held an approximately nine percentage point lead over independent and former state governor Andrew Cuomo — with 50.4 per cent to 41.6 per cent — while Republican Curtis Sliwa received 7.1 per cent.

In Virginia and New Jersey, moderate Democrats Abigail Spanberger, 46, and Mikie Sherrill, 53, won the elections for governor with commanding leads, respectively.

The contests offered a barometer of how Americans are responding to Trump’s tumultuous nine months in office.

The races also served as a test of differing Democratic campaign playbooks before 2026, with the party locked out of power in Washington and still trying to forge a path out of the political wilderness.

Perhaps the biggest practical boost to Democrats came out of California, where voters gave Democratic lawmakers the power to redraw the state’s congressional map, expanding a national battle over redistricting that will shape the race for the US House of Representatives.

The winning candidates could re-energise and inspire more engagement from Democratic voters, many of whom have clamoured for fresh faces at the vanguard of the party.

All three Democratic candidates emphasised economic issues, particularly affordability, an issue that remains top of mind for most voters.

But Spanberger and Sherrill hail from the party’s moderate wing, while Mamdani used a viral video-fuelled insurgent campaign to present himself as an unabashed progressive in the mould of senator Bernie Sanders and US representative Alexandria Ocasio-Cortez.

“The Democratic Party is back,” Hakeem Jeffries, the Democratic leader in the US House of Representatives, assrted on X.

Mamdani, who will become the first Muslim mayor of the biggest US city, outlasted Cuomo, 67, who ran as an independent after losing the nomination to Mamdani earlier in 2025.

Cuomo, who resigned as governor four years ago after sexual harassment allegations that he has denied, portrayed Mamdani as a radical leftist whose proposals — such as raising taxes on corporations to pay for policies such as frozen rents and free city buses — were unworkable and dangerous.

Republicans from Trump down have already signalled they intend to present Mamdani as the face of the Democratic Party.

-with AAP