In November — as President Trump began his effort to overturn the election he had lost — his longtime friend Tom Barrack called him with advice: Stop, for the sake of your business.

The Trump Organization was already struggling, hurt by political backlash and coronavirus-related closures, facing huge unpaid loans. Barrack told Trump that he could help that business — as well as his aides, and the country itself — by ensuring a peaceful transition, according to a person familiar with the conversation.

An “elegant” exit, Barrack said, could preclude what could be a painful future: millions of dollars in legal costs, rampant investigations and more boycotts of his businesses.

Trump did not follow Barrack’s advice.

Now, the Trump Organization is facing the consequences: In the past week, it has lost a bank, an e-commerce platform and the privilege of hosting a world-famous golf tournament, and its hopes of hosting another have been dashed. In the future, the Trump Organization also could lose its D.C. hotel and even its children’s carousel in Central Park, if government landlords in Washington and New York reevaluate their contracts with Trump.

Trump lost a much bigger broker relationship Tuesday night when real estate giant Cushman & Wakefield told The Washington Post it would no longer work with him. The company has handled an array of business for Trump for many years, including office leasing at Trump Tower and 40 Wall Street, and retail leasing in Chicago. It means that Trump’s company will quickly have to find someone else to handle lease negotiations at some of his most prominent properties.“Cushman & Wakefield has made the decision to no longer do business with The Trump Organization,” the company said in a statement.

By refusing to acknowledge that he would be returning to private life, Trump appears to have sabotaged what could have been his best chance at success in that realm — a rebound of the battered Trump brand.

The Post’s Devlin Barrett outlines the potential charges President Trump and his legal team may face for inciting a mob to breach the U.S. Capitol on Jan. 6. (The Washington Post)

Now, through his encouragement of rioters who ransacked the U.S. Capitol, Trump has made his company a pariah and driven away allies who could have brought it revenue and post-politics credibility.

“Most financial institutions and investors avoided doing business with him before he ran for president, and the situation now has only gotten worse,” said Kathryn Wylde, the leader of the Partnership for New York City, an influential group that includes the leaders of banks and Fortune 500 companies.

Wylde was able to secure support for an open letter against Trump’s efforts to overturn the election from almost 200 major companies — including most of the major banks and real estate firms in New York — within 36 hours, a sign of how angry many are with his actions. That was before Jan. 6.

“If he remains a visible player, no one will want to be associated with him in any kind of public way, because he is going to symbolize the destabilization of the American political system,” Wylde said.

The Trump Organization did not respond to requests for comment Tuesday. The White House declined to comment.

One senior administration official said Trump was particularly infuriated about the PGA of America’s decision to move the 2022 PGA Championship away from Trump’s Bedminster, N.J., golf course. Trump wanted to know what legal rights his company had to stop the organization from moving it.

The official, speaking like some others on the condition of anonymity to comment candidly, said Trump had been a bit “shellshocked” at the corporate backlash to his comments preceding the attack on the Capitol.

A former senior administration official said that Trump has long wanted regular updates on how his businesses are performing — particularly his Mar-a-Lago Club and the Bedminster golf club. “The happiest I saw the president was when all the biggest people in business were around him and kissing his ring,” the former official said, citing one particular event in Florida where real estate honchos and others each paid $580,000 to Trump’s campaign.

Trump still owns his organization but has given day-to-day leadership to his sons Donald Jr. and Eric. The company has not said what Trump’s role there will be after he leaves office Jan. 20.

Even if Trump had conceded his race to Biden without drama, he would have returned to a company that had been diminished — literally and metaphorically — since he took office in January 2017.

Four Trump-branded hotels had closed. The company’s plans for new hotel chains had fizzled. The remaining hotels had been hit by political backlash, and then by the pandemic, which has devastated the hospitality industry: At Trump’s Chicago hotel in the fall, the managing director told investors, “It’s going to be very, very tough to keep the boat afloat.”

The D.C. hotel’s BLT Prime restaurant had quietly lost its decorated chef, David Burke, who told The Post on Tuesday that he left in the fall after ESquared Hospitality, the New York-based company that operates the upscale steakhouse, ended his contract. Burke said it was probably because of the economics of the pandemic.

Trump has at times railed about business losses resulting from his being president, a senior administration official said, complaining in the Oval Office that the scrutiny and bad publicity were costing him “billions.”

Trump also is facing state-level investigations into his financial practices in New York, and more than $400 million in loans will come due in the next few years.

That was bad. But as of Election Day, Trump still had partners who could help him recover.

Then came the attack on the Capitol.

The first backlash fell upon, of all things, the Trump website that sells candles and T-shirts.

TrumpStore.com had been hosted by the e-commerce website Shopify — until last week.

“Shopify does not tolerate actions that incite violence,” the company said. As of Tuesday evening, the site was still down.

Then Trump lost the real estate broker working to sell his D.C. hotel. He lost the PGA Championship, one of golf’s four majors, which was scheduled to be played at his Bedminster, N.J., club in 2022. The event would have given him a massive spotlight in a sport he loves.

In Britain, Trump’s hopes of landing another major golf tournament — the British Open — were dashed, as the organizers said they would not use Trump’s Turnberry club in Scotland for “the foreseeable future.”

This week, Trump lost his accounts at New York’s Signature Bank, which gave back the money and put out a statement telling him to resign. New York City said it was “reviewing whether legal grounds exist” to terminate Trump’s contracts for ice rinks, the carousel and the city-owned golf course.

Also Tuesday, Professional Bank — a Florida entity that lent Trump’s company $11.2 million in 2018 to buy the president’s sister’s home near Mar-a-Lago — said it would no longer do business with Trump.

“Professional Bank has decided not to engage in any further business with the Trump Organization and its affiliates, and will be winding down the relationship effective immediately,” the bank said in a statement. Trump also has a money market account at the bank worth at least $5 million, according to his most recent financial disclosure. The bank’s decision was first reported by the Wall Street Journal.

That may not be the extent of Trump’s troubles.

He still owes that $400 million, much of it to Deutsche Bank. Under normal circumstances, a borrower might seek to refinance or extend those loans, perhaps by getting a loan from a different bank. But experts say the former president is likely to have extreme difficulty finding a Wall Street bank willing to refinance properties that he controls.

At Deutsche Bank, which had bailed Trump out of financial hardships before, his personal banker resigned recently. And his existing loans with Deutsche Bank are on properties that have suffered severely from pandemic-related business closures. The New York Times reported that Deutsche Bank had determined it would not do business with Trump in the future. A Deutsche Bank spokesman declined to comment to The Post.

Also, at one of Trump’s most troubled and debt-saddled properties, he will soon have a new landlord: the Biden administration.

Trump’s D.C. hotel operates in the federally owned Old Post Office building under a contract with the federal government. For several years, therefore, Trump has effectively been his own landlord — and a fairly understanding one.

Since Trump was elected, the General Services Administration, which oversees the lease, has approved his ownership — despite a clause saying the lease could not benefit an elected official — and blocked House Democrats’ inquiries into the hotel. The GSA has said Trump is in compliance because he wasn’t an elected official when he signed the lease.

One of those Democrats, House Transportation and Infrastructure Committee Chairman Peter A. DeFazio (Ore.) said Tuesday that he hoped Biden’s team would release documents to show whether Trump derived improper benefits from the contract while president.

“My Committee’s investigation has not ended — it was stonewalled. I expect our records requests to be honored by the Biden administration,” DeFazio said in a statement to The Post.

Still, Trump’s D.C. hotel struggled: Company documents obtained by The Post said the hotel had been running nearly half-empty, even before the pandemic, The Post has reported. The company sought to sell the operation, then pulled it off the market after the novel coronavirus hit. Trump borrowed about $170 million from Deutsche Bank to renovate the building.

Now some experts think the Biden administration may have grounds simply to revoke the lease, particularly if Trump runs into further legal trouble. One clause in the contract says Trump would be in violation if he is “under investigation by any government authority for alleged criminal activity” — meaning federal or D.C. agencies.

Steven Schooner, an expert on contract law at George Washington University, said that should be enough.

“By law and regulation, our government need only do business with contractors that ‘have a satisfactory record of integrity and business ethics,’ ” Schooner said. Schooner said Biden’s administration should sever the contract.

“At a moment when major private-sector firms, concerned for their reputations, are publicly disassociating the Trump Organization like rats from a sinking ship, this isn’t rocket science,” he said.

A Biden transition spokesman declined to comment.

As of Tuesday night, Eric Trump had not tweeted at all since the day of the Capitol attack. The Trump Organization’s official Twitter account has been silent since Jan. 1, when it wished the world a happy new year.

Tim Carman contributed to this report.