When President Donald J. Trump left office, some of Wall Street’s biggest names, who had taken to him during his first term in the White House, swore they were moving on from him for good. They were fatigued by his leadership style, disappointed by some of his policies and shocked by the U.S. Capitol riot. Some of them even savaged him publicly.

Their stated distaste didn’t last. With Mr. Trump leading in the polls, big financiers on Wall Street, in Silicon Valley and elsewhere are edging into his corner, according to interviews with more than a dozen people who sought anonymity because they didn’t want their personal views to be tied to their employers.

The motivations are manifold. In many instances, it’s less that they’re enthusiastic about Mr. Trump — “I still hate the man,” one hedge fund billionaire said — and more that they’re exasperated with the economic and immigration policies of President Biden. In other cases, the willingness to support a return of Mr. Trump reflects a growing dissatisfaction with what many big Wall Street donors see as the White House’s hardening stance against Israel in its war on Gaza.

A prominent example of the about-face is Kenneth Griffin, a hedge fund magnate and political megadonor who publicly derided Mr. Trump as a “three-time loser” less than two years ago. In recent weeks, the Citadel founder has been in communication with the former president’s campaign about potentially making a major donation, which would amount to millions of dollars.

Asked by The New York Times if he would support Mr. Trump for the first time in 2024, Mr. Griffin said: “It’s a question I’m giving serious consideration to.”

In an interview with Bloomberg News on Tuesday, Mr. Griffin said Mr. Trump “will exude a level of strength” that would help settle foreign policy issues, among others.

Mr. Griffin and his representatives have told the Trump campaign that the billionaire is waiting to see whom the former president selects as his vice-presidential candidate. He is hoping for a pick with close ties to the traditional Republican apparatus, such as Nikki Haley, the former governor of South Carolina. Mr. Griffin donated millions to Ms. Haley’s unsuccessful presidential campaign in the Republican primary race.

More than a dozen bankers, asset managers, hedge fund titans, lawyers and venture capitalists, including attendees of the $25,000-a-head Milken Institute Global Conference this month, said that they were disappointed by Mr. Biden’s economic and border-control policies. They requested that their names and titles be withheld so that they could share their views freely.

Their concerns reflect longstanding gripes about inflation and a rise in illegal immigration that have long dragged on the president’s approval ratings. More recently, however, some have added exhaustion at the various legal proceedings against Mr. Trump (not all of which involve the federal government) and dismay over the Biden administration’s flagging support for Israel in the Gaza conflict.

The potential groundswell of deep-pocketed support for Mr. Trump could be critical for his campaign, given that its fund-raising considerably lags Mr. Biden’s. At the same time, any redirection of funds from the Biden campaign could hurt it further, given the president’s political predicament: Many big donors are put off by his softening support for Israel, even as other voters want him to be far tougher on Israel for its invasion of Gaza.

Polling results released this week by The New York Times, Siena College and The Philadelphia Inquirer showed that young and nonwhite voters were turning away from the incumbent because they saw his policies as too supportive of Israel.

Millionaire and billionaire political donors who are reconsidering Mr. Trump include not just longtime Republican boosters returning to back the party’s presumptive nominee but donors like Mr. Griffin who steered clear of the former president in his two prior runs for the White House.

In some ways, the well-to-do class isn’t so different from the electorate, as polls have shown Mr. Trump leading in the majority of battleground states. Those figures have been largely unchanged since late last year. Also, big-time donors of all political stripes often move to support leading candidates in races.

Big business was hardly part of Mr. Trump’s political base in either 2016 or 2020. Corporate leaders came out vociferously in early 2021 against his attempts to interfere with the transfer of power; the largest bank in America, JPMorgan Chase, responded by pausing all political donations, and its chief executive, Jamie Dimon, said Mr. Trump had been “gassing up a mob.”

Mr. Dimon turned heads across Wall Street in January when he told CNBC from the World Economic Forum in Davos, Switzerland, that Mr. Trump had been “kind of right” about a number of issues, including taking a tougher stance toward China and passing tax cuts. The bank’s political action committee, funded by employees including Mr. Dimon, has since resumed its giving and handed out more this election cycle to Republicans than to Democrats.

In interviews, other senior Wall Street executives and political donors said they felt that Mr. Dimon’s comments had provided cover for them to back Mr. Trump more openly.

Mr. Dimon declined through a bank spokesman to elaborate, but that spokesman, Joe Evangelisti, said Mr. Dimon’s point was, “We should not be disrespectful to 75 million fellow Americans just because they agree with some policies of a presidential candidate.”

A Trump campaign spokesman did not respond to requests for comment. A Biden campaign spokeswoman pointed to the president’s recent fund-raising trip to the West Coast, which she said had raised $10 million from Silicon Valley founders and executives.

There remains a difference between what some prominent businesspeople will say publicly and privately about Mr. Trump, who has challenged norms by vowing to investigate political rivals if he is returned to the Oval Office.

Last month, a group of technology heavyweights including Elon Musk, the venture capitalist Marc Andreessen and the investor Peter Thiel gathered for a dinner during which they discussed how best to oppose a second Biden term, two people briefed on it said. The dinner was reported earlier by the newsletter Puck.

Mr. Andreessen, who once said Mr. Trump’s immigration plans left him “sick” to his stomach, later told investors from the Middle East that he would not support Mr. Biden, one person who was told of the meeting said. That’s further than what Mr. Andreessen has said publicly.

A spokeswoman for Mr. Andreessen declined to comment on those remarks and said he wouldn’t take sides publicly. “Marc talks about current events in casual settings all the time, like every other normal human being,” said the spokeswoman, Margit Wennmachers.

Mr. Thiel, one of Mr. Trump’s biggest boosters in 2016, has said he does not plan to donate this time around, though he has vented privately about Mr. Biden’s management of the economy, according to three people who have spoken with him about the topic. Yet Mr. Thiel’s data analytics firm, Palantir Technologies, recently met with a representative of the Trump campaign to discuss the candidate’s potential return to the White House, two people briefed on the sit-down said.

The political environment is also creating some odd bedfellows for Mr. Trump. Take Cliff Asness, a billionaire hedge fund manager and self-described libertarian who as recently as this year called the Republican Party a “cult” under the former president.

Last week, after the White House paused an arms shipment to Israel to prevent them from being used in an assault on the tightly populated Gazan city of Rafah, Mr. Asness wrote on X that he was “perilously close to the formerly (and still kind of) unthinkable: #TRUMP2024.”