New York City, America’s most innovative metropolis when it comes to making life harder than it needs to be, is about to perform that service for the national Democratic Party. As Democrats go to the polls to choose their next candidate for mayor, the big question is whether they will make their party’s path back to power in Washington rockier by only a little bit, or by a lot.

Polls show an overcrowded race narrowing to two candidates who are ideal only as foils for one another. Neither would dispel the cloud darkening the Democrats’ image when it comes to local governance. At the far left, perpetually smiling, is Zohran Mamdani, a 33-year-old Democratic Socialist with scant experience in leadership but grand plans. Towards the centre, glowering, is Andrew Cuomo, one of the more effective but also most scarred of Democratic politicians. He resigned in his third term as governor, in 2021, over accusations of sexual harassment that he denies.

Mr Cuomo, at 67 more than twice his rival’s age, is running as the reliable choice for New Yorkers who want their streets safer and their trash picked up. Yet not just his history of scandal but his long experience itself repels the college-educated, young white voters who are increasingly important in Democratic primaries in New York, as across the country. For them, he reeks of the past.

To these voters, Mr Mamdani—with his proposals for free bus services and city-run grocery stores, his censure of Israel and his artful TikTok videos—could have been dreamed up to embody the future by a benign Silicon-Valley genius, if they thought one existed. Mr Mamdani, a member of the state Assembly, would be the first immigrant mayor of New York in generations, and the first Muslim ever. He has mobilised thousands of volunteers, while Mr Cuomo has relied on a lavishly funded super-PAC. At a rally for Mr Mamdani on June 14th, Representative Alexandria Ocasio-Cortez said a vote for him would “turn the page” to a party that “does not continue to repeat the mistakes that have landed us here”.

For Democrats rallying to Mr Cuomo, Ms Ocasio-Cortez and Mr Mamdani are making the mistakes, dragging the party down by alienating working-class voters with Utopian schemes that neglect fear of crime and frustration with high taxes and poor services. Mr Mamdani has run a disciplined campaign focused on affordability, and he has revised some past positions, such as defunding the police. Yet polls show Mr Cuomo receiving far more support from black and Latino New Yorkers, as Jacobin, a socialist magazine, noted. “We need to become more organically connected with the working-class constituency we hope to help organise,” the writer observed, in a timeless lament of the high-toned left.

Early voting is under way ahead of election day, June 24th. In all, 11 candidates are competing, under a ranked-choice voting system that makes the outcome hard to predict. Most candidates share Mr Mamdani’s contempt for Mr Cuomo, and they have been urging supporters not to include him among their five possible choices. Another of the many progressives, Brad Lander, the city’s comptroller, may have cut into Mr Mamdani’s support by getting arrested in front of reporters on June 17th while challenging federal agents to produce a warrant to detain an immigrant.

In the presidential election last autumn Kamala Harris sank under the burden of left-wing positions she took in the past, while moderate Democrats down-ballot outperformed more extreme candidates. Subsequently, conventional political wisdom appeared to be taking hold that the party needed to reclaim the political centre; Democrats with national ambitions have been deleting their “preferred pronouns” from their social-media bios. On June 10th, in one bellwether race, Democrats in New Jersey chose a moderate congresswoman, Mikie Sherrill, as their nominee for governor. But as the race in New York shows, Democrats’ identity and direction are far from settled questions, and much of the party’s dynamism and imagination remain with the left.

Donald Trump’s electoral success is driving the intraparty debate even as his actions in office create superficial unity. The candidates uniformly say they will resist Mr Trump, unlike the current Democratic mayor, Eric Adams, who extended some co-operation as Mr Trump’s Justice Department moved to dismiss corruption charges against him. Mr Adams, whose support has collapsed, plans to compete as an independent in the general election. The Democratic nomination is usually enough to secure the mayoralty, but, should Mr Cuomo or Mr Mamdani lose the primary, either could also run on another party’s lines, prolonging this struggle.

Mr Adams’s pliability may explain why Mr Trump has yet to be as aggressive in New York as in Los Angeles. That is likely to change under the next mayor. Mr Cuomo, who like Mr Trump grew up in what was then the white ethnic Queens of Archie Bunker, touts his toughness, with reason; he is a bulldozer whose biggest obstacle has usually been himself. Mr Trump would not easily bait him into the political fights he loves (such as arresting Democrats who can be portrayed as grandstanding and obstructing justice).

For his part, Mr Mamdani declared in one debate, “I am Donald Trump’s worst nightmare, as a progressive Muslim immigrant who actually fights for the things that I believe in.” That is probably wrong. Mr Mamdani lives in Queens, but in the multi-ethnic, hipster oasis it is today. He grew up on the Upper West Side, the son of a professor of anthropology and an Oscar-nominated filmmaker. That may help explain why, like Mr Trump, he is such an adept social-media performer. But as a legislator he has delivered just three minor pieces of legislation, and nothing on his résumé suggests he is ready to competently deploy the city’s 360,000 workers or its $112bn budget. As New York’s mayor he is a leftist’s dream—and that makes him Mr Trump’s dream, too.