Expert explains why Trump's threat to cut NYC federal funds after Mamdani's win would be illegal

An expert has broken down why Donald Trump's threat to block federal funding to New York City after Zohran Mamdani's mayoral victory would be illegal.

Mamdani beat fellow runners Andrew Cuomo and Curtis Sliwa on Tuesday night (November 4), receiving 50.4 percent of the vote compared to their 41.6 and 7 percent respectively, as per the BBC.

The 34-year-old Democrat is the youngest person elected as New York's mayor in a century, as well as the first Muslim and South Asian.

Describing himself as a 'Democrat socialist,' Mamdani is pushing to make the US' most populated city more affordable.

His policies include increasing taxes on the city's wealthiest, increasing publicly subsidized housing and freezing stabilized apartment rental rates.

Prior to his historic win, however, President Donald Trump threatened to hold back federal funds for his hometown should Mamdani be elected.

Trump threatened to cut New York City's federal funding should Mamdani win (Kevin Dietsch/Getty Images)

Trump, who grew up in the affluent Jamaica Estates in Queens, claimed he would only send 'the very minimum' level of federal funding to the city.

Instead, he threw his support behind independent candidate Cuomo, who served as governor between 2011 and 2021, resigning after numerous sexual misconduct allegations, all of which he denies.

Why would stopping federal funding be illegal?

The US Constitution actually gives Congress, not the president, the power to decide how federal money is distributed to states.

At the moment, Republicans control Congress, with 53 Republicans in the Senate and 220 in the House of Representatives.

Article I, Section 8 allows Congress to collect taxes and decide how money should be spent, while Article I, Section 9 says no money can leave the US Treasury unless Congress has approved it.

If a president refuses to spend money that Congress has already allocated, it’s called 'impoundment', and it’s unconstitutional.

Trump himself grew up in New York City (CHARLY TRIBALLEAU/AFP via Getty Images)

To prevent this, the Impoundment Control Act of 1974 was created after President Nixon tried to withhold approved funds.

The law allows the president to delay spending for up to 45 days, but Congress must approve that decision, meaning Congress still has final authority.

Speaking to Al Jazeera, constitutional lawyer Bruce Fein said that a president can’t legally cut off funding to a state unless Congress has set clear conditions tied to the purpose of the money. For example, a president can’t stop Medicaid payments just because a governor belongs to another political party.

If that happened, the affected state or organization could sue the federal government.

A report from the New York State Comptroller, released in April, says New York City will need about $7.4 billion in federal funds for the 2026 financial year.

This federal money makes up 6.4 percent of the city’s total spending, while the rest comes from state taxes, fees, and other revenue sources.

Mamdani won 50.4 percent of the vote (Adam Gray/Bloomberg via Getty Images)

What has Mamdani said about Trump?

Mamdani addressed Trump directly in his victory speech, telling the president to 'turn up the volume'.

"We will hold bad landlords to account because the Donald Trumps of our city have grown far too comfortable taking advantage of their tenants," he continued. "We will put an end to the culture of corruption that has allowed billionaires like Trump to evade taxation and exploit tax breaks.

"We will stand alongside unions and expand labor protections because we know, just as Donald Trump does, that when working people have ironclad rights, the bosses who seek to extort them become very small indeed.

“New York will remain a city of immigrants, a city built by immigrants, powered by immigrants and as of tonight, led by an immigrant. So hear me, President Trump when I say this, to get to any of us, you will have to get through all of us.”