In 1982, when Donald Trump was 36 years old, he began an annual ritual of lobbying Forbes magazine to include him on its list of the 400 wealthiest Americans. Forbes debuted the list that year, and Trump pursued his inclusion with gusto — lying, cajoling and repeatedly jumping on the telephone to make sure that a young reporter at the magazine, Jonathan Greenberg, would accept his inflated claims about how much money he had.

Greenberg taped a few of those phone calls and he published them as part of a longer reflection in The Washington Post on April 20 describing what it was like to be conned by Trump.

“It took decades to unwind the elaborate farce Trump had enacted to project an image as one of the richest people in America,” Greenberg wrote. “Nearly every assertion supporting that claim was untrue. Trump wasn’t just poorer than he said he was. Over time, I have learned that he should not have been on the first three Forbes 400 lists at all.”

Greenberg’s column is a reminder that Trump has been running a very long con on the American public, and it raises a question that now has an urgency it didn’t decades ago: How long can the long con last?

Trump’s shtick in its early days was limited to New York, and most New Yorkers (who, of course, have good antennae for such things) knew it was awash in snake oil.

Yes, Trump might say he was a business titan worthy of the Forbes 400. But he wasn’t among the upper echelon of New York real estate developers, he wasn’t a fixture of civic life and he seemed more at home on Page Six than on the front page of The Wall Street Journal.

Trump’s love of the con — borrowing billions he couldn’t repay so he could invest in splashy properties and projects he didn’t understand — drew national attention and blanket media coverage just before the game unraveled in serial bankruptcies in the early 1990s.

After that debacle, Trump refashioned himself as a ubiquitous media curiosity, one who held center stage in part by being the one famous guy who could reliably be called upon to chat about sex, women and even his own genitals.

Trump’s emergence on “The Apprentice” in 2004 enabled him to extend the con once again. He had been spinning myths about being a can-do businessman for years, but the show allowed him to play an entrepreneurial guru in front of millions of people each week. Although it soon fizzled, Trump used the show to refashion himself as a calculating executive — one who some thought might just be talented enough to shake up the federal government.

I wrote a biography of Trump at the peak of his fame, and he later sued me for libel because, among other things, the book scrutinized his years of patty-cake with Forbes to get on its rich-list while also raising doubts about whether he was a billionaire. (Trump lost the case in 2011.)

During a deposition, Trump conceded that he was so broke at one point that he had to borrow millions of dollars from his father’s estate to avoid personal bankruptcy — something he had earlier contested when I asked him about it during our many conversations for the book. (“I had zero borrowings from the estate,” Trump told me. “I give you my word.”)

Greenberg mentioned my reporting as one reason why he came to realize that Trump had hoodwinked him over the years, and cited documents that were available to me but not to him when he was at Forbes.

Even without those documents, though, there were plenty of reasons to doubt Trump’s honesty — and Forbes’ methodology. Between 1982 and 1983, for example, the magazine allowed the Trump family’s stated real estate fortune to double from $200 million to $400 million, even though a savage recession was underway. In 1989, Forbes ranked Trump 26th on its list, then dropped him entirely a year later. He was gone for five years and then resurfaced with $450 million in 1996. That jumped to $1.4 billion a year later. And so on.

You don’t need tape recordings to understand this con. You just need common sense.

When I asked Trump in 2005 about his obsession with the Forbes 400 and with being perceived as a billionaire, he was dismissive. “It seems to be that they’re the barometer of individual wealth. It doesn’t really matter. It matters much less to me today than it did in the past.”

That was false, of course. About a decade later, Trump would brag about being worth more than $10 billion while he was running for president. Trump has latched onto such fanciful figures not simply because he’s insecure about his wealth, but because he knows that pretending he has that kind of money keeps him in the media’s eye and keeps potential business partners interested in him. It’s all part of the long con.

That con now has global consequences. Trump doesn’t fulminate about North Korea or building a wall on the Mexican border because he’s a policy maven with deeply held principles.

It’s because he knows that toying around with sensitive and sometimes dangerous subjects gets the media’s attention and keeps certain blocs of voters interested in him.

That’s part of the long con too. And the president will keep it up — and get away with it — as long as voters play along.

Timothy L. O’Brien is the executive editor of Bloomberg Gadfly and Bloomberg View.