Donald J. Trump’s top hotel executive is leaving the company as its five-star signature hotel brand has taken a back seat to other moneymaking ventures by the former president.

The executive, Eric Danziger, cited family reasons for his departure. He joined Trump Hotels in 2015 with plans to expand the business, but instead oversaw the shrinking of a significant portion of the hotel portfolio as Mr. Trump’s polarizing politics tarnished the brand, legal and ethical scrutiny scared away potential partners, and the pandemic sent the hospitality industry into a tailspin.

Since 2017, the Trump name has come off hotels in New York, Toronto, Panama, Vancouver and, soon, Washington D.C., as once-lucrative deals were canceled or sold. Trump hotels, for decades a defining feature of the former president’s global real estate business, have dwindled to seven properties. Any immediate hope of rebuilding the hotel brand after Mr. Trump left office was likely undone by the fallout from the Jan. 6 attack on the Capitol, as many companies parted ways with the Trumps.

Mr. Danziger, 67, announced his departure on Wednesday in an email to colleagues in the hotel industry, where he has been a prominent figure for decades. He said he would become chief executive of Braintree Group, a company in Boise, Idaho, that has several lines of business, including hospitality. The email noted that he owns a home in Boise and has a son who works for Braintree.

In an internal email to the Trump Organization obtained by The New York Times, Mr. Danziger thanked the Trump family for always being “incredibly supportive,” adding, “I will always cherish my time here.”

Mr. Trump’s company, the Trump Organization, did not immediately respond to a request for comment.

Mr. Danziger’s tenure coincided with a period of deep turmoil for the business, including a series of congressional and law enforcement investigations that put a crimp in expansion plans.

His departure is part of a broader reshuffling of the company’s executive ranks. Mr. Trump’s longtime chief financial officer, Allen H. Weisselberg, lost his title last year after he was indicted, along with the Trump Organization itself, on tax fraud charges. Mr. Weisselberg remains at the company in a lesser role.

The moves put what was already a tight-knit company further in the hands of the Trump family. Mr. Trump, once he became president, largely turned over the company to his son Eric, who already oversaw its generally successful golf division.

Since leaving office, Mr. Trump has leveraged his political popularity in some quarters to pursue entirely new business endeavors, from a social media platform to a multimillion-dollar advance on a $75 dollar coffee table book. These lines of revenue are separate from the Trump Organization’s core real estate business, which includes the hotels, 16 golf clubs and a variety of commercial real estate properties that have been among its biggest moneymakers.

Before Mr. Trump entered politics, he presided over the company without a chief executive to lead the hotel group.

In 2015, the Trump family recruited Mr. Danziger for a job that had the looks of a capstone on a nearly 50-year career that had seen Mr. Danziger rise from a hotel bellman to a top executive at Starwood, Carlson and Wyndham. But by the time the family announced Mr. Danziger’s appointment, in August of that year, Mr. Trump’s presidential campaign had begun, and there were already signs his divisive politics would take a toll on business.

Even so, Mr. Danziger’s team began laying the groundwork for growth. They scouted deals in China and the Middle East, while planning the rollout of two new down-market hotel brands in the United States — Scion and American Idea — aimed at capitalizing on Mr. Trump’s popularity in red states and towns outside of big cities.

The two new domestic brands took on greater importance after Mr. Trump was elected president and declined to divest from his business, but adopted a self-imposed ban on new deals in foreign countries.

Mr. Danziger, in a March 2017 interview with The New York Times, spoke bullishly about the new hotel lines, saying the company had signed 30 letters of intent with potential developers. “To the extent that the presidency has had any effect on us it might be in one or two hotels that would have protests or whatnot,” he said. “We’re running a business. We’re running brands; we’re adding brands.”

That summer, the Trumps hosted a reception in New York in the atrium of Trump Tower to introduce new hotelier partners from the Mississippi Delta. But no other deals materialized, and two years later, the Trumps scrapped that partnership and abandoned the new brands, blaming the political climate.

The political toxicity of the Trump name in some of its key markets also forced the company to retreat.

Partners in Trump-branded hotels in New York and Toronto paid the family to walk away and removed their name from the buildings. A spectacle emerged at a hotel in Panama as a new owner kicked out the Trump employees and had the letters T-R-U-M-P removed with a hammer and crowbar. The company that owns the Vancouver hotel, which opened in 2017, eventually declared bankruptcy.

The Trump Organization has a deal to soon sell its marquee Washington hotel, which became a hub for lobbyists and Trump loyalists during his presidency. The deal, worth at least $375 million, is expected to turn a profit for the family.

The remaining signature hotels are in Chicago, Honolulu, Las Vegas and New York, and the company operates luxury golf resorts in Florida, Scotland and Ireland.

With business stagnant during the presidency, the Trumps began managing a New Jersey hotel owned by the family of Jared Kushner, Mr. Trump’s son-in-law and a top adviser in his administration. The two families also discussed partnerships related to a development in Long Branch, N.J. Mr. Danziger described it at the time as a “straight-up business deal,” but soon it fell apart amid ethics questions.

Upon Mr. Trump’s leaving the White House, Mr. Danziger was free to resume the expansion of the hotel brand. But the Jan. 6 attack on the Capitol created new setbacks. The series of criminal and civil investigations have also left the company in limbo.

At Braintree, Mr. Danziger will oversee a broader array of businesses, including mid-scale hotels, residential properties and charter schools. Jason Kotter, a co-founder of Braintree, said Mr. Danziger “will bring a depth and breadth of executive prowess.”