For Ron DeSantis, Sunday, Feb. 19, was the start of another busy week of not officially running for president.

That night, he left Tallahassee on a Florida hotelier’s private jet, heading to Newark before a meet-and-greet with police officers on Staten Island on Monday morning. Next, he boarded a twin-jet Bombardier to get to a speech in the Philadelphia suburbs, before flying to a Knights of Columbus hall outside Chicago, and then home to his day job as governor of Florida.

The tour and others like it were made possible by the convenience of private air travel — and by the largess of wealthy and in some cases secret donors footing the bill.

Ahead of an expected White House bid, Mr. DeSantis has relied heavily on his rich allies to ferry him around the country to test his message and raise his profile. Many of these donors are familiar boosters from Florida, some with business interests before the state, according to a New York Times review of Mr. DeSantis’s travel. Others have been shielded from the public by a new nonprofit, The Times found, in an arrangement that drew criticism from ethics experts.

Mr. DeSantis, who is expected to formally announce his candidacy next week, is hardly the first politician to take advantage of the speed and comfort of a Gulfstream jet. Candidates and officeholders in both parties have long accepted the benefits of a donor’s plane as worth the political risk of appearing indebted to special interests or out of touch with voters.

But ethics experts said the travel — and specifically the role of the nonprofit — shows how Mr. DeSantis’s prolonged candidate-in-limbo status has allowed him to work around rules intended to keep donors from wielding secret influence. As a declared federal candidate, he would face far stricter requirements for accepting and reporting such donations.

“Voters deserve this information because they have a right to know who is trying to influence their elected officials and whether their leaders are prioritizing public good over the interests of their big-money benefactors,” said Trevor Potter, the president of Campaign Legal Center and a Republican who led the Federal Election Commission. “Governor DeSantis, whether he intends to run for president or not, should be clearly and fully disclosing who is providing support to his political efforts.”

Representatives for the governor’s office and for Mr. DeSantis’s political operation declined to comment or provide details about who has arranged and paid for his flights.

Mr. DeSantis has aggressively navigated his state’s ethics and campaign finance laws to avoid flying commercial. And he has gone to new lengths to prevent transparency: Last week, he signed a bill making travel records held by law enforcement, dating back to the beginning of his term, exempt from public records requests.

Mr. DeSantis is still required to report contributions and expenses in his campaign finance records, but the new law probably prevents law enforcement agencies from releasing more details, such as itineraries, flight information or even lists of visitors to the governor’s mansion. (Mr. DeSantis says he is trying to address a security concern.)

In February, Mr. DeSantis traveled to Newark on a jet owned by Jeffrey Soffer, a prominent hotel owner who, according to several lawmakers and lobbyists, has sought a change in state law that would allow him to expand gambling to his Miami Beach resort.

The February trip and others were arranged by And To The Republic, a Michigan-based nonprofit, according to Tori Sachs, its executive director. The nonprofit formed in late January as Mr. DeSantis was beginning to test the national waters and quickly became a critical part of his warm-up campaign. It organized nearly a dozen speaking events featuring the governor in at least eight states.

Ms. Sachs would not say how much was spent on the flights or who paid for them.

It is unclear how Mr. DeSantis will account for the trips arranged by the nonprofit without running afoul of state ethics laws. Florida generally bars officeholders from accepting gifts from lobbyists or people, like Mr. Soffer, whose companies employ lobbyists — unless those gifts are considered political contributions.

But both Ms. Sachs and a person involved in Mr. DeSantis’s recent travel said they did not consider the trips political contributions or gifts. The person was not authorized to discuss the matter and spoke on condition of anonymity. The group’s practice “is to provide transportation for special guests,” Ms. Sachs said, “in full compliance with the law.”

Florida ethics rules, however, give politicians plenty of loopholes. In some circumstances, for example, officeholders can accept paid travel to give speeches as part of their official duties. The state ethics commission has also allowed officeholders to accept gifts from lobbyists if they are channeled through third-party groups.

Since taking office in 2019, Mr. DeSantis, who has worked in public service his entire career and reported a net worth of $319,000 last year, has steadily leaned on others to pick up the tab for private flights.

His political committee has accepted private air travel from roughly 55 wealthy, mostly Florida-based contributors and companies associated with them, including the heads of oil and gas companies, developers and homebuilders, and health care and insurance executives, a Times analysis of campaign finance records shows.

Additional travel donations were routed to the Republican Party of Florida, which Mr. DeSantis often used as a third-party pass-through.

A half dozen lobbyists and donors who spoke with The Times said they became accustomed to calls from the governor’s political aides asking for planes — in at least one case, for a last-minute trip home from out of state and, more recently, for a flight to Japan.

The Japan trip, which was part of an overseas tour that gave Mr. DeSantis a chance to show off his foreign policy chops, was considered part of the governor’s official duties and was organized in part by Enterprise Florida, a public-private business development group. But Mr. DeSantis’s office would not disclose how it was paid for or how he traveled. Enterprise Florida did not respond to requests for comment.

Mr. DeSantis’s office rarely releases information about nonofficial events. (In February, when he traveled to four states in one day, his public schedule simply read, “No scheduled events.”) And Mr. DeSantis has brushed off past criticism of his travel. In 2019, The South Florida Sun Sentinel revealed a previous flight to New York on a plane owned by Mr. Soffer. Mr. DeSantis said he had followed proper procedures.

“It’s all legal, ethical, no issues there,” he told reporters.

A spokeswoman for Mr. Soffer declined to comment.

Soon after winning re-election in November, the governor turned to building his national profile. He began traveling the country to visit with Republican activists, dine with donors, speak at events and promote a new book, “The Courage to Be Free: Florida’s Blueprint for America’s Revival.”

Some of his travel was paid for by Friends of Ron DeSantis, a Florida political committee that supported his campaign for governor and reports its donors. The committee had more than $80 million on hand as recently as last month — money that is expected to be transferred to a federal super PAC supporting his presidential run.

Since November, that committee has received 17 contributions for political travel from nine donors. They include Maximo Alvarez, an oil and gas distributor, and Morteza Hosseini, a Florida homebuilder who has frequently lent his plane to the governor and has become a close ally.

But trips paid for by the nonprofit group, And To The Republic, do not appear in state records.

The group is registered as a social welfare organization under Section 501(c)(4) of the federal tax code, meaning its primary activity cannot be related to political campaigns. Other prospective and official presidential candidates also have relationships to similar organizations, often called dark money groups because they are not required to disclose their donors.

The nonprofit’s founder, Ms. Sachs, said it was formed to promote “state policy solutions that are setting the agenda for the country” and described Mr. DeSantis as one of the first elected officials to “partner” with the group. Another of those officials, Gov. Kim Reynolds of Iowa, has appeared at the group’s events in her home state — alongside Mr. DeSantis.

And To The Republic has hosted Mr. DeSantis at events in South Carolina, Nevada and Iowa, all key early primary states. Some of those events were promoted as “The Florida Blueprint,” borrowing from Mr. DeSantis’s book title.

The arrangement has made tracking Mr. DeSantis’s travel — and its costs — difficult. The Times and other news outlets used public flight trackers to verify the governor’s use of Mr. Soffer’s plane, which was first reported by Politico.

Other trips arranged by the group include the Feb. 20 stops outside Philadelphia and Chicago and the return trip to Tallahassee, on which Mr. DeSantis flew on a plane registered to a company run by Charles Whittall, an Orlando developer. Mr. Whittall, who gave $25,000 to Mr. DeSantis’s political committee in 2021, said that he uses a leasing company to rent out his aircraft, and that he did not provide it as a political contribution.

In March, he traveled to Cobb County, Ga., on a plane owned by an entity connected to Waffle House, the Georgia-based restaurant chain. The company did not respond to a request for comment.

Other potential DeSantis rivals have made headlines for their use of private jets. Both as South Carolina governor and as ambassador to the United Nations, Nikki Haley faced criticism for flying on private planes owned by wealthy South Carolinians.

In 2020, The Associated Press reported that donors gave hundreds of thousands of dollars in private air travel to Donald J. Trump’s fund-raising committee. The donors included Ben Pogue, a Texas businessman whose father later received a presidential pardon.

Still, Mr. Trump — who owns his own plane — has repeatedly sought to draw attention to Mr. DeSantis’s travel, claiming the private planes were effectively campaign contributions and “Ron DeSantis is a full-time candidate for president.”

Shane Goldmacher and Michael C. Bender contributed reporting. Kitty Bennett and Sheelagh McNeill contributed research.