Lee Zeldin’s surprisingly strong campaign for New York governor has been fuelled by an obsessive focus on crime and lawlessness that has resonated with an anxious public.

It has also been sustained by millions of dollars from the billionaire Ronald Lauder.

Earlier this year, Zeldin, a Republican congressman and ardent supporter of Donald Trump, was considered an afterthought in a state where Democrats dominate when Lauder, an heir to the Estée Lauder cosmetics fortune, began writing seven-digit cheques.

Those contributions helped keep Zeldin’s campaign afloat and have since allowed him to take the fight to a well-funded incumbent, Kathy Hochul. Days before Tuesday’s midterm elections, he is within striking distance, according to opinion polls, of pulling off what would arguably be the biggest upset of this political season. In a sign of Democrats’ concern, vice-president Kamala Harris flew in to campaign with Hochul late last week and president Joe Biden is expected on Sunday.

“Lee Zeldin was roadkill and then Ronald Lauder came along,” a New York political strategist said. “Win or lose, he owes his entire campaign to him. No one else was there.”

Lauder’s contributions, totalling more than $11mn as of October 28, are a vivid example of the outsize influence that the very wealthy can wield in US elections following the Supreme Court’s 2010 decision to lift campaign spending restrictions on corporations and outside groups.

“Billionaires are sponsoring candidates like prized racehorses,” Michael Waldman, president of the Brennan Center for Justice at New York University law school, recently wrote, citing nearly $30mn in donations this election season by the technology investor Peter Thiel.

For Lauder, the question is what has motivated such largesse for Zeldin? Other longtime New York Republicans passed on his campaign — either because they thought it was hopeless or they were too troubled by his vote against certifying Biden’s 2020 election victory.

The two men — a 42-year-old product of the middle class and a 78-year-old art patron and heir of extreme wealth — are not said to be close. Still, there are obvious overlapping interests between the candidate and his benefactor.

Zeldin would be New York’s first Jewish Republican governor and has been a staunch defender of Israel against a growing legion of progressive critics. That should appeal to Lauder, president of the World Jewish Congress, who has made it a mission to restore Jewish life in central and eastern Europe and has long been at the forefront of American support for Israel.

Criminal justice is also a shared passion. Zeldin was raised in a family of law enforcement officers in a modest Long Island hamlet before serving in Iraq and then training as a lawyer. He has made crime the centrepiece of his campaign, promising to fire Manhattan’s reformist district attorney and roll back recent legislation that has made it more difficult for police to detain and hold suspects.

Zeldin’s message appeared to break through to voters after a dramatic event in early October, when two teens were wounded in a drive-by shooting outside his suburban home while his daughters were inside studying.

Lauder wrote a book in 1985, when his native New York was gripped by lawlessness, called Fighting Violent Crime In America. It argued that business and management expertise should be applied to address crime. One of the two political action committees he founded and has used to support Zeldin through a barrage of anti-Hochul advertising is called Safe Together New York.

Murders and shootings in New York City rose sharply during the coronavirus pandemic, although they are still well below historic highs from the early 1990s. While both categories have begun to ease in recent months, auto theft and other crimes are rising, creating a confusing picture.

Yet statistics may not convey the unease generated by random assaults on the subway and several incidents of people being shoved on to the train tracks by deranged assailants. In response, Hochul announced a plan in September to install security cameras in subway cars.

There is another, less savoury theory about Lauder’s interest in Zeldin. It concerns an offshore wind farm project called South Fork. It has become an obsession for the billionaire and his neighbours in Wainscott, an exclusive oceanfront corner of the Hamptons, because the transmission line for the turbines would come ashore on their property. They have waged a campaign to have it altered — so far to no avail.

Lauder raised South Fork with Hochul late last year, according to several people briefed on the matter. The former lieutenant-governor had been recently thrust into the governor’s mansion after the resignation of Andrew Cuomo. Hochul, a Buffalo native, was little known and held introductory meetings with civic and business leaders.

The new governor promised to look into the matter, according to these people, but ultimately rebuffed Lauder, concluding that South Fork — a critical part of New York’s clean energy policy — was too far advanced. In February, she visited Wainscott to announce the beginning of construction.

Through a spokesperson, Lauder declined to comment. A person familiar with his thinking strongly denied that South Fork played a role in his support for Zeldin. This person said it was almost entirely based on crime and concerns that wealthy New Yorkers, who pay a disproportionate share of city taxes, were fleeing because a Democratic-controlled state legislature had failed to address public safety.

“This is less about Lee Zeldin and more that Kathy Hochul is not leading in the right direction,” this person said, noting Lauder’s concern about one-party rule in the state.

Hochul’s office declined to comment. During a recent debate, she alluded to Zeldin’s relationship with Lauder, saying: “What worries me is the fact that you have one billionaire donor who’s given you over $10mn.”

A Zeldin spokesperson did not respond to requests for comment.

Ronald Lauder took a secondary role at the family business to his older brother, Leonard, and has spent his years tacking between interests in art, politics, diplomacy and the good life.

He was appointed ambassador to Austria in 1986 by president Ronald Reagan, and at one point conducted back-channel negotiations for a possible Syria-Israel peace deal. In addition to major holdings of Austrian and German art, Lauder has amassed one of the world’s foremost collections of armour, which he recently donated to the Metropolitan Museum of Art.

“He doesn’t have any inhibitions about being wealthy and spending money,” his friend Richard Parsons, the former Time Warner chief executive, told the New Yorker magazine in 2007. “Ronald is the exemplar of ‘I am not going to die with all this cash if I can help it.’”

In 1989, Lauder, a close ally of former senator Al D’Amato, spent a then-record $14mn challenging Rudolph Giuliani for the Republican nomination for New York City mayor. He was beaten by a more than 2:1 margin, with each vote he won costing him about $368.

His financial backing for Trump proved successful but came at a cost. It was motivated, say closer observers, by a shared hawkishness about Israel. Yet it stirred worry at Estée Lauder about damage to the company’s brand. Angry employees launched a petition demanding that Lauder be removed from the board.

“He’s been sort of the political black sheep of the family,” a New York political consultant observed.

Now, with Zeldin — and crime — Lauder has found a long-shot political investment that, even opponents acknowledge, could deliver a big pay-off.

This article has been amended since first publication to make clear that Lee Zeldin would be New York’s first Jewish Republican governor