Jan. 16, 2017 Martin Luther King III, son of civil rights leader Martin Luther King Jr., exits an elevator at Trump Tower in New York with President-elect Donald Trump. Mark Abramson/for The Washington Post

In Manhattan, the setting for Donald Trump’s reality-TV show and campaign headquarters now serves as the president-elect’s base of operations.

The setting for Donald Trump’s reality TV show and campaign headquarters now serves as the president-elect’s base of operations.

The setting for Donald Trump’s reality TV show and campaign headquarters now serves as the president-elect’s base of operations.

Happy hour had just started in the Trump Bar, just off the lobby of Trump Tower, and nearly every seat was filled in the formerly sleepy establishment. A couple sipped $10 martinis as a red campaign hat sat on the bar next to them. A group of guys with $5 beers filled a table, all of their bodies turned toward the four gold elevators in the lobby.

Hours earlier on Tuesday, Vice President-elect Mike Pence and his wife, Karen, walked through the bar en route to a meeting with the soon-to-be president upstairs, leaving a motorcade waiting just outside the bar door. Throughout the day, there was a parade of men in suits who looked important, creating a never-ending game of “Guess Who?” for the gawking media and actual gawkers.

Just then, there was a commotion by the elevators as Trump’s second of three wives — Marla Maples — emerged, rushed past reporters and left through the Trump Bar.

Trump Tower is where Donald Trump lives and works. It was the setting for his reality television show and the headquarters of his presidential campaign. And now, as he prepares to become president, this is where Trump is building his administration.

Unlike a private office building, the lobby of Trump Tower was legally designated as a public space as part of a deal that Trump struck with the city in the late 1970s and must be accessible to members of the public from 8 a.m. to 10 p.m. That has forced the Secret Service and the New York City Police Department to devise an elaborate protection plan for at least the next two months.

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There is a no-fly zone over Trump Tower, and the police have barricaded sidewalks near the building, creating a maze for those wanting to enter. Inside there are security checkpoints where bags are scanned, and visitors are wanded. Although Trump says he wants to get rid of gun-free zones on his first day in office, weapons are banned in his tower.

Trump has a history of using this public space for his own financial gain, and he was fined in 2006 and 2015 for setting up kiosks to sell his own merchandise, according to the Associated Press. Months into Trump’s campaign for president, he continued to operate two kiosks in the lobby, where he sold campaign merchandise alongside Trump-branded gear. Those pop-up shops vanished by the spring, and in late May, New York City officials investigated whether Trump was blocking members of the public from the atrium when he held news conferences and primary-night celebrations. As soon as that happened, Trump stopped hosting formal events here.

Now the Trump Tower atrium is busier than ever. When the doors open to the public at 8 a.m., there is usually a swarm of reporters waiting to get inside. They spend the day sitting on a row of metal benches set up across from the elevators, watching who is coming and going, interviewing possible Cabinet members and trying to keep tabs on the president-elect, who rarely leaves.

There are rules of decorum: no sitting on the ground, and no putting your feet on the benches or standing on them to take a photograph.

Most reporters were on their feet all of Tuesday, trying to determine who was attending Trump’s casting call.

First came the campaign workers turned transition staffers. Trump’s oldest son, Donald Trump Jr., arrived holding a pair of athletic shoes. Deputy campaign manager Michael Glassner rolled in with a suitcase. Beyond pleasantries, none wanted to talk to reporters.

Vice President-elect Mike Pence arrived at Trump Tower for talks about the transition from President Obama’s administration to President-elect Donald Trump’s administration on Nov. 15 in New York. (The Washington Post)

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Then came the potential Cabinet members. Sen. Jeff Sessions (R-Ala.), who has advised Trump for months, strolled in and chatted with a few reporters about how this is “such an exciting time.” He jumped into a packed elevator when the questions turned to his possible role in the administration.

Steven Mnuchin, a former Goldman Sachs Group partner who is advising Trump, walked up to reporters and said he is helping the president-elect prepare to “get the biggest tax bill passed, the biggest tax changes since Reagan.” But he demurred when asked about rumors that he is in the running for treasury secretary: “I’m not going to comment.”

Whenever there was a lull in the traffic, a janitor wearing a bow tie and dinner jacket would rush in to mop the marble floors, which were especially difficult to keep clean that day as rain poured. At one point, security personnel put up a red velvet rope to better corral the ever-growing group of reporters.

As the day wore on, more and more tourists arrived, taking photos of the media and asking who famous might be there that day. Two tourists from Belgium hung around for nearly an hour but left when told the media had not laid eyes on Trump since late last week. Two other tourists from Italy provided unsolicited political punditry.

At 11:28 a.m., Pence’s motorcade pulled up outside the Trump Bar long after its expected arrival time. Out came the vice president-elect, his wife and an entourage of aides and security. Pence waved but did not say anything. When he left more than six hours later, he said just four words: “Great day! Great day!”

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At lunchtime, the food court in the building’s basement — reached using the famous escalator that once carried Trump down to his announcement speech in June 2015 — was packed with police officers, journalists, tourists and a few people who actually work in the building.

As the afternoon progressed, retired Lt. Gen. Keith Kellogg stopped by to let reporters know that it would be inappropriate for him to comment on the transition process or anything happening upstairs but that everything is going “great, great.”

“He’s going to be a great president,” Kellogg said. “He’s got a great team. He’s got great people.”

As Kellogg listed everything that is great, Peter Thiel — a libertarian Silicon Valley billionaire who leads a venture capital firm — sneaked into the lobby and quietly got on an elevator without the media noticing.

Soon there was another lull, and a bow-tied man vacuumed the carpet, while a mother from Alabama and her two daughters asked reporters for directions. Fashion designer Tommy Hilfiger was spotted, although he has an office in the building and was probably headed there.

Then, just before 4 p.m., Maples — Trump’s second wife who barely seems to have aged since they divorced in 1999 — was spotted at the Starbucks on the second floor, taking photos with people who recognized her. Soon, she was in the elevator, presumably headed to see Trump. Less than 30 minutes later, she was back in the lobby and walking quickly toward the Trump Bar.