Andres Serrano has been quietly stockpiling buttons, baked goods, liquor bottles, slot machines, sports memorabilia, menswear and magazine covers.

For almost a year, his tremendous collection effort has taken him to the front row of high-end auctions and to the far reaches of eBay. The artist best known for his 1987 “Immersion (Piss Christ),” an amber-hued image of a crucifix submerged in a glass container of his own urine, has spent more than $100,000 amassing a treasure trove of more than 1,000 objects.

Each item bears some relationship to President Trump. They include souvenirs from his hotels and casinos, as well as merchandise from his 2016 presidential campaign. They include Trump Vodka, Trump Steaks and remnants of Trump Shuttle. They include a Trump University diploma and a fake dollar bill depicting Hillary Clinton behind bars, to which Trump affixed his signature at a Florida rally.

“Trump everything,” the divisive New York-based artist, whose creations have been vandalized at museums across the world and reviled in Congress, said in an interview with The Washington Post. “I wanted to paint a portrait of Donald Trump using his own brushes.”

The untraditional presidential portrait is set to be revealed April 11 at a still-undisclosed location in Manhattan.

The installation, titled “The Game: All Things Trump,” is an image of the president rendered in his varied acts of salesmanship and self-promotion. It is a Trump readymade, in the model of Marcel Duchamp, the 20th-century pioneer of avant-garde art.

By carefully cataloguing the artifacts as if in a natural-history museum, the exhibition is also a study of the United States as a competitive, acquisitive and fame-obsessed society. Intentionally or not, “The Game: All Things Trump” helps answer the question that stumped pundits and defied polls: How did Trump become president?

“I’ve always said I don’t make art about art” said Serrano, whose work aims to fuse the sacred and the profane, in his first public remarks about the exhibit. “I make art about things that everyone knows about. It’s only natural that it’s now Trump.”

The show’s title is drawn from “Trump: The Game,” a 1989 board game released by Milton Bradley Co., with the tagline, “It’s not whether you win or lose, but whether you win!”

“That has been the Donald Trump attitude all his life,” said Serrano, 68, who was born in New York — four years after the president — to an immigrant father from Honduras and a mother of Afro-Cuban descent.

The boom-or-bust mentality espoused by the president, the artist said, has been central to the pursuit of the American Dream, which Trump declared “dead” at his presidential launch in June 2015. Before it died, a dreamlike sense of possibility guided Serrano’s own path. He dropped out of high school when he was 15, entered the Brooklyn Museum Art School when he was 17, spent his later teen years and much of his 20s addicted to drugs and then “came out of it and became the artist that I thought I was supposed to be.”

The president’s life, too, embodies an American ideal — in a different sense. “When I was in my 20s, I was a drug addict,” Serrano said. “When he was in his 20s, he already owned a lot of things.”

The Trump-branded commodities, the artist believes, are an index of the president’s beliefs and aspirations. In Serrano’s eyes, they reveal how Trump’s quest to identify himself with the country — to cast himself as an American hero — began long before he undertook a bid to lead it.

“Ever since the ’80s, Donald Trump has been associating himself with a particular vision of American success and making products that paint him as all-American,” Serrano said.

The first object that the artist acquired for the installation was a red-and-white-striped Donald J. Trump Signature Collection tie. The second and third were buttons from the 2016 campaign. All together, the collection documents the president’s vast commercial empire — among the many features distinguishing the 45th president from his predecessors. One of them, Jimmy Carter, famously placed his peanut farm in a blind trust during his presidency to avoid possible conflicts of interest.

When it emerged in February that Serrano had purchased a chocolate truffle cake, handed out as a souvenir at Trump’s 2005 wedding, the art world buzzed with speculation about what the artist, whose photographs often feature violence and desecration, had in store for the confectionery delight.

Cedric Barberet, formerly the executive pastry chef at Mar-a-Lago, was curious, too.

“I’m worried about what will happen with what I created,” he said in an interview with The Post at the time.

But all Serrano did to the miniature cake, which he purchased in an auction for $1,880, was build a refrigerated cube for it.

“I’m not doing anything to these products,” he said. “That’s the beauty of them — they speak for themselves.”

The exhibition neither glorifies nor condemns the president. Serrano, who first photographed Trump for his 2004 “America” series, doesn’t pass moral judgment on his subject.

“I’m not interested in pointing figures, because I think it’s boring,” he said. “I’ve seen a lot of artwork that’s anti-Trump, and frankly it’s not good, it’s not interesting. I’d rather let the man speak for himself.”

This is a fitting aim for an artist who has never been especially involved in the political process, as he readily admits, despite being “engaged by the circus that we see in American politics now.”

He has only voted twice in his life — for Barack Obama in 2008 and again in 2012 — and he doesn’t plan to vote again.

“He seemed pretty good, and so I felt like just out of loyalty to the race, I had to support this black president,” Serrano said. The possibility of another breakthrough in 2020 — the first female president, the first black female president, the first openly gay president — wouldn’t motivate him in the same way, he said.

Asked whether he thought Trump was a good president, he demurred.

“I think he’s Donald Trump, and that says it all,” Serrano observed. “It says that he’s always been good at selling things, particularly himself. And he’s done it once again.”

If he could speak with the president, all he would ask is that Trump sign his large black bible in gold magic marker. He thinks it would make a good addition to the installation.

As an artist, he said, he keeps his views to himself, letting his audience come to its own interpretation. There is only one piece in the upcoming show that he created — the 2004 portrait of Trump, an imposing close-up slotted in the celebrity section of the series, begun after the Sept. 11 attacks to try to say something about the American spirit.

The rest of the objects were merely assembled by him. Serrano likes the idea that other people, such as the former Mar-a-Lago pastry chef, could go around the exhibit and say, “I did that. I did that.”

Meanwhile, viewers will find in the objects figments of their previous connections to Trump — whether they watched him on “The Apprentice,” gambled at his casinos, bought his vodka or even went to Trump University. They are part of his rise, Serrano said.

He thinks Trump would like the show, too. “It’s all about him,” the artist said. “I couldn’t have done it without him.”

“I wish Donald Trump would see the show and say, ‘Gee, that’s a good show, you know, I did a lot of good things,’ and then maybe feel better about himself, so he can chill,” Serrano said. “In a way, you gotta say, ‘Donald Trump, you won. There’s no sense fighting us. You won.’”

In a bid for the president’s attention, and that of his most avid followers, he hopes to place a 15-second advertisement on some of Trump’s favorite channels, including Fox News.

Serrano said “The Game: All Things Trump” has all the hallmarks of his best work, including simplicity and beauty. Whether he is photographing hooded Klansmen or murder victims, naked bodies or homeless people, firearms or feces, his glossy pictures make his subjects “beautiful and bigger than life,” he said.

Of all the criticism he receives — and he receives his fair share — Serrano said he most resents the notion that his work is sacrilegious. For decades, he has been a bête noire of the religious right, in the United States and around the world. In 2011, Catholic fundamentalists took hammers to “Piss Christ” when it was on display in the French city of Avignon.

“I was born and raised a Catholic, and I did my holy communion and then my confirmation, were I was told I was a soldier of God,” Serrano said. “I’m still that soldier of God."

Still, he acknowledged, “People see it how they want to see it. I accept it.”

He expects that reactions to his Trump show could be as severe and as various.

“It’s a show for everyone — for people who love Trump, and for people who hate Trump,” he said.

Serrano’s work addresses basic themes, he said, enumerating a few of them: death, religion, sex, poverty. He likes to make things that people can understand on a visceral level.

It was inevitable, then, that he would turn to Trump, perhaps the most capacious theme of all.

He wanted to paint a big picture, and the president offered a broad canvas.

“In a way, Donald Trump has become all things to all people,” Serrano said.

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