New York elects its new mayor on Tuesday and the favorite in the polls is Zohran Mamdani, a 34-year-old Muslim of Indian origin, from the left wing of the Democratic Party and a "fierce" opponent of Donald Trump.

The US president has regularly taken a position in the campaign and on Monday evening called for a vote for Mr. Mamdani's main opponent, the former governor of the state, Andrew Cuomo.

"Whether you personally like Andrew Cuomo or not, you really don't have a choice. You have to vote for him and hope he does a fantastic job. He's capable of it, Mamdani isn't!", Mr. Trump wrote Monday night on his Truth Social network.

"If the communist candidate Zohran Mamdani wins the election to become mayor of New York, it is very unlikely that I will contribute federal funds, except for the bare minimum required," Mr. Trump warned.

Polling stations open at 6:00 AM (11:00 AM GMT) and close at 9:00 PM (2:00 AM GMT Wednesday). Lincoln Mitchell, a professor at Columbia University, expects high voter turnout for this "hotly contested" election.

For months, polls have given Zohran Mamdani the advantage, recently showing a lead of 4.5 to 16 points over Andrew Cuomo. Mr. Mamdani is running as an independent after losing the Democratic primary.

The third man, Republican Curtis Sliwa, stubbornly refused to withdraw in favour of Andrew Cuomo, whose pro-business and security positions were close to his own.

Some 735,300 voters cast their ballots early, four times more than in the last municipal election in 2021 which mobilized a total of 1.15 million people (a turnout of 23.3%).

Early voting, a recent trend in New York, is attracting new voters, but it "can (also) be a sign of strong enthusiasm for a candidate or concern about the outcome of the election," notes John Kane of New York University.

The election of its 111th mayor, who will take office on January 1st, is mobilizing more than five million voters in the largest city in the United States, including more than 60% Democrats.

"Political enemies"

Zohran Mamdani's proposals (rent control, free buses and nurseries) are more in line with social democracy.

While the Republican president has deployed the army in several Democratic strongholds (Portland, Chicago, Washington, Memphis and Los Angeles), Zohran Mamdani has promised to "fiercely" oppose his anti-immigration policy and his legal war against his "political enemies".

Elon Musk, too, called for a vote for Andrew Cuomo, rather than "Mumdumi or whatever his name is", on X on Monday.

Even within his own party, the candidate is not unanimously supported. Several figures, notably the leader of the Democratic senators, New Yorker Chuck Schumer, do not publicly endorse him, and those who have done so have been cautious.

Although he was late in endorsing Zohran Mamdani, the leader of the Democrats in the House of Representatives, Hakeem Jeffries, does not think he is "the future" of their party, despite the enthusiasm he generates in New York.

Experts interviewed by AFP agree, pointing to the specific nature of New York political life compared to the rest of the country.

Obama's compliments

Former Democratic President Barack Obama, for his part, "praised the campaign" of the young socialist during a phone call on Saturday, according to the New York Times. Like Zohran Mamdani himself, he denounced "Islamophobic" attacks from some of Andrew Cuomo's supporters.

Neighboring New Jersey is also choosing its next governor, between Republican businessman Jack Ciattarelli and the Democrat considered more moderate, Mikie Sherrill.

The state was considered a Democratic stronghold for the past decade. But in the last presidential election, Donald Trump significantly narrowed the gap.

Virginia, meanwhile, is set to elect its first female governor. Polls show Democrat Abigail Spanberger, a former CIA agent, with a slight lead over Republican Winsome Earle-Sears, a former Marine. But here too, the margin and voter turnout will be closely watched.

On the other side of the country, Californians are voting on whether to authorize a redrawing of the state's electoral map that will favor the Democratic Party, in response to a similar Trumpian initiative in Texas.