Republican presidential frontrunner Donald Trump met with GOP leaders and surveyed the progress made on his new luxury hotel under construction in downtown Washington on Tuesday. (WUSA9)

If Donald Trump ever leads a tour of the White House, Jackie Kennedy-style, it might go something like this:

“It’s going to be fantastic,” the billionaire said Monday, standing amid piles of lumber and squinting up at the facade of the Old Post Office Pavilion in downtown Washington. “That window is from 1880. Hard to believe, right? For the most part, we were able to use the same glass, because it’s special glass. It has a kind of patina.”

In a surreal break from a jam-packed day of political events, the GOP presidential front-runner paused his campaign a few blocks from the White House he hopes to occupy in order to show off the patch of Pennsylvania Avenue he is remaking: his $200 million conversion of this aged federal icon into a luxury Trump hotel.

Sorry, not just “luxury.”

“Super luxury, and it’s going to be amazing,” Trump said to a group of reporters crowded into the building’s freezing atrium, still draped in plywood and plastic sheeting. “That’s a brand new floor; in about a week it gets covered with marble, beautiful marble from different parts of the world.”

Squeezed among a morning meeting with Republican lawmakers, an hour-long interview with The Washington Post’s editorial board and an evening speech to a pro-Israel conference, Candidate Trump briefly reverted to Salesman Trump and spent more than an hour pointing out details of the Romanesque Revival edifice that will soon be the Trump International Hotel.

“The exterior of the building is granite, some of it four- or five-feet thick,” Trump said, as reporters chaffed to ask about Israel and immigration. He promised close to 300 “super luxury” rooms in “one of the truly great hotels in the world,” where rates for the most basic rooms will start at $795 a night.

He seemed to equate his hotel with a national monument. “As people who love this country, I think you’re going to be very proud of this,” said Trump, who was flanked by a construction worker in a hard hat, a chef in kitchen whites and assorted suited executives.

Outside, a crowd of about 50 had gathered under a billboard-size sign that has marked the construction site for months. It reads: “Coming 2016 TRUMP.”

Some cheered as his motorcade drove to a side entrance and they caught a glimpse of the mogul waving from behind a tinted window. One vendor sold Trump buttons.

About a dozen protesters, most from the activist group Code Pink, called out “Trump has got to go” and “Stop the violence, stop the hate.” D.C. police officers pushed them back onto the sidewalk after they stepped into the street. No arrests were made.

About a dozen protesters, most from the activist group Code Pink, demonstrate outside the Old Post Office Pavilion in downtown Washington, where Donald Trump spoke Monday about his renovation of the building into a hotel and shopping complex. (Michael S. Williamson/The Washington Post)

“He is playing people for real suckers just like Hitler did scapegoating minorities,” said 68-year-old protester David Barrows before donning a suit of cash and an oversize caricature Trump head.

If Trump wins the presidency, he would arguably be the first builder to occupy the White House since architect Thomas Jefferson brought his Palladian vision to the Federal City. But, judging by the high points of the Post Office walk-through, Trump’s vision is less neoclassical than neo-classy.

“We are going to have the largest suites in Washington,” he said, as he led the scrambling scrum of reporters out a side door, through a crowded alley where a construction lift was parked and through the skeleton of bare 2-by-4s that will soon be “one of the biggest ballrooms in Washington . . . and by far the most luxurious.”

Trump’s Secret Service detail hustled, unsuccessfully, to keep a perimeter around the candidate as he dragged journalists through the cluttered construction site. Cameramen elbowed and women in high heels struggled with plywood and potholes.

“God . . . there goes my coat,” said one after catching her garment on the edge of an aluminum 2-by-4.

Asked during a pause in the parade what kind of changes a President Trump might make to the White House, he would only say: “I’d leave it the way it is.”

District leaders were euphoric in 2013 when Trump signed a 60-year lease on the hulking 19th-century edifice that had deteriorated into a grimy food court that sporadically hosted middle-school tour groups. His promise to convert the building into a world-class hotel and shopping complex was seen as key to rejuvenating the Pennsylvania Avenue corridor.

But Trump’s explosive, divisive presidential campaign has tempered that enthusiasm in a city that is largely African American, internationally diverse and overwhelmingly Democratic.

Council member Charles Allen (D-Ward 6) asked city officials to remove the outsize Trump sign from the site as “inappropriate” political advertising.

Last summer, Washington celebrity chef José Andrés pulled out of the project, saying he couldn’t open a restaurant in the hotel after Trump disparaged Mexican immigrants as criminals, drug dealers and rapists.

Trump hit Andres’s company, ThinkFoodGroup, with a $10 million lawsuit for breach of contract. The chef responded with an $8 million countersuit, asserting that it was Trump’s anti-Hispanic blasts that ruined the business prospects for a Spanish restaurant.

When asked during the tour what impact Andres’s departure would have on the project, Trump shook his head dismissively. “We have a phenomenal replacement,” he said.

In September, Trump’s company announced that BLT Prime, a sister company to BLT Steaks, would operate a signature restaurant in the hotel.

But some local leaders remain delighted with Trump’s ability to saw through the bureaucratic logjam that had stalled renovation of the Old Post Office for years. The General Services Administration, National Park Service and various historic preservation boards have jurisdiction over the property.

Although his contract calls for the hotel to open by 2018, Trump said Monday he expects to swing the doors wide in September, two months before the election.

“I would say the GSA and the Park Service move at a glacial pace, but that would suggest some movement at all,” said D.C. Council member Jack Evans (D-Ward 2). “They move at no pace. If he indeed delivers this on time and under budget, that’s quite an achievement.”

Evans, a supporter of Democratic presidential front-runner Hillary Clinton, said there could be some advantages to physical Washington should Trump take over the government. The sale of the Federal Bureau of Investigation headquarters on Pennsylvania Avenue and its relocation is another of many federal real estate projects that could use a jolt, he said.

“I sit in some of these meetings and just want to scream,” Evans said. “Maybe he would actually have the wherewithal to get some of these things done.”

Fenit Nirappil contributed to this report.