NEW YORK — Trump Tower, once the crown jewel in Donald Trump’s property empire, now ranks as one of the least desirable luxury properties in Manhattan.

The 36-year-old building has been turned into a fortress since Trump won the presidency, ringed with concrete barriers and the two main entrances partially blocked off. It hasn’t been substantially updated in years. And Trump’s name has been a huge turnoff in liberal New York City.

For anyone who owns a unit in the tower, the past two years have been brutal. Most condo sales have led to a loss after adjusting for inflation, property records show. Several sold at more than a 20 percent loss. By contrast, across Manhattan, just 0.23 percent of homes over the past two years sold at a loss, according to PropertyShark, a real-estate data provider.

It’s all a far cry from the days when the New York landmark attracted the likes of Michael Jackson, Johnny Carson and Steven Spielberg. These days, it’s better known for a Trump campaign meeting with a Russian lawyer documented in special counsel Robert Mueller’s Russia report.

While some corners of Trump’s business empire have thrived, such as his Washington, D.C., hotel, others have suffered from his high unpopularity. Rounds of golf are down at his public course in New York, a clutch of once Trump-branded buildings have torn his name off their fronts, and an ambitious plan to launch a new mid-tier hotel chain across the country fizzled.

The commercial portion of the building has been struggling for months to find tenants for more than 42,000 square feet of vacant office space, despite advertising rents well below the area’s average, listings and data from real estate brokers show.

On any given midweek afternoon, the number of government and Trump Organization security personnel rivaled the number of other people inside the building’s atrium.

Trump Tower’s occupancy rate has plunged over the last seven years to 83 percent from 99 percent, giving it a vacancy rate that’s about twice Manhattan’s average.

“If I were looking for office space, that would be a building I’d want to avoid,” said Edward Son, until recently a market analyst for CoStar Group Inc.

Net income slightly rose last year, boosted by the tenancy of his 2020 campaign committee, which has spent more than $890,000 over the last two years to rent space in Trump Tower, according to Federal Election Commission records.

The building’s net income is still about 26 percent lower than what bankers expected when they evaluated Trump’s fitness for a $100 million loan in 2012. Even so, Trump Tower regularly produces an annual profit for its namesake. Last year, the building generated $10 million in net cash flow, after taking into account its annual $4.3 million interest payment on the loan, according to Trump Organization disclosures.

The Trump Organization didn’t respond to requests for comment.

Condo owners hoping to run into the president on occasion have been disappointed. While Trump ran his presidential campaign out of the high-rise, he’s only visited 13 times since his inauguration, according to a count from NBC News.

Michael Sklar sold his parents’ 57th floor unit for $1.83 million in October after they spent $400,000 to remodel the property. His family purchased it for $1.4 million in 2004, which comes out to $1.84 million after adjusting for inflation.

After Trump’s election, living in his tower became a hassle, Sklar said. His mother, who was battling cancer, took cabs to the building from the airport, and she used to be dropped off right in front of the entrance. After the election, security would force her cab driver to drop her off a few hundred feet from the front door, requiring a long and painful walk home.

“The name on the building became a problem,” Sklar said.

At least 13 condos in the tower have sold since Trump’s 2016 election, property records show. For the nine transactions where New York City records show what the seller originally paid for the property, eight sold at an inflation-adjusted loss.

By contrast, just 57 homes in Manhattan sold over the past two years at a loss, out of 24,871 third-party sales, according to PropertyShark, although the firm doesn’t adjust for inflation.

One New York real estate agent, who didn’t want to be identified discussing Trump, said that clients have repeatedly told him not to show them units in Trump buildings.

These days, gawkers sometimes outnumber the customers of the building’s remaining retail stores.

“It’s totally a tourist trap,” said Barbara Res, a former Trump Organization executive who oversaw the building’s construction.

Res remembers the building fondly, and said that when it was built Trump recruited celebrities to purchase its condos and prominent brands to fill its retail space. “It’s dated but it’s a building worthy of respect,” Res said.

Located just two blocks from Central Park, Trump built his namesake tower in 1983, complete with a 60-foot waterfall and mounds of pink Italian marble.

Advertised as having 68 stories — it’s actually 58, city records show — the building was ahead of its time, Trump’s lawyer, George Ross, wrote in his 2005 book, “Trump Strategies for Real Estate.” “He single-handedly created the market for high-end luxury residences in New York City,” Ross wrote.

The office portion of Trump Tower is advertising five vacancies spread across five floors. In January, prices for the open space ranged from $72 to $85 per square foot annually.

Now the prices are listed as negotiable.

“Any of the buildings that have been really successful in Midtown are either newer class or the landlords have spent considerable capital to make them more modern and have more amenities,” said Louis D’Avanzo, managing principal of Cushman & Wakefield Plc’s Midtown Manhattan office.

Trump hasn’t spent much money updating Trump Tower in recent years, according to disclosures to investors.

“I don’t think I would want an office in Trump Tower,” Res said. “Why would you go there? It’s a wonder he doesn’t have 50 percent vacancy.”