Buffett was asked by a Notre Dame student about Trump's business troubles during a question-and-answer session in 1991. Trump's Atlantic City Taj Mahal casino filed for Chapter 11 bankruptcy protection later that year.
"Where did Donald Trump go wrong? The big problem with Donald Trump was he never went right. He basically overpaid for properties, but he got people to lend him the money. He was terrific at borrowing money. If you look at his assets, and what he paid for them, and what he borrowed to get them, there was never any real equity there," Buffett said, according to a transcript published by former hedge fund manager Whitney Tilson.
"I've seen more people fail because of liquor and leverage – leverage being borrowed money. Donald Trump failed because of leverage. He simply got infatuated with how much money he could borrow, and he did not give enough thought to how much money he could pay back."
Value investing aficionados are enthusiastically discussing the Oracle of Omaha's timeless investing tips and wisdom as Berkshire Hathaway's annual meeting approaches in early May. Discussion about Buffett's 1991 comments on leverage and Trump gained traction Wednesday on social media.
Buffett also told the students to instead use his own life as a model on how to succeed in business and investing without using much debt.
"You really don't need leverage in this world much. If you're smart, you're going to make a lot of money without borrowing," he said. "I've never borrowed a significant amount of money in my life. Never. Never will. I've got no interest in it."
The investor's sage advice on leverage has not changed over the years.
Buffett repeated his warning and told investors not to use debt to buy stocks in his 2017 annual letter to Berkshire Hathaway shareholders released in February and during an interview with CNBC a few days later.
"It is crazy in my view to borrow money on securities," he told CNBC. "It's insane to risk what you have and need for something you don't really need. ... You will not be way happier if you double your net worth."
Berkshire Hathaway did not immediately respond to a request for comment.