Republican presidential nominee Donald Trump. (Carlo Allegri/Reuters)

“I MEAN, who does that?” That was the question posed by Hillary Clinton at the last presidential debate about Donald Trump’s use of charitable funds to purchase a six-foot portrait of himself. We now have a fuller answer to that question. It is someone who uses $264,631 of foundation funds to renovate a fountain outside one of his luxury hotels. It is someone who pulls a bait-and-switch on a public school chess team. It is someone who shamelessly hogs the spotlight at a charity function for sick children without having given a dime. Mr. Trump’s approach to charity is that of a charlatan — further evidence of a lack of character that makes the Republican nominee uniquely unfit for the Oval Office.

Mr. Trump’s philanthropic track record has been the subject of a series of reports by The Post’s David A. Fahrenthold. Among the findings: Mr. Trump’s namesake foundation has largely been funded with other people’s money and has been involved in a series of questionable actions, including possible violation of laws against self-dealing that prohibit nonprofit leaders from using charity money to benefit themselves (e.g., using foundation funds to settle lawsuits involving Mr. Trump’s business ventures). The Post reports prompted scrutiny by the New York attorney general, who ordered the charity to cease soliciting donations because it lacked the proper licensing.

The latest revelations center on Mr. Trump’s machinations to make himself seem more generous than he is, making showy promises that were never kept. Hence his commandeering a front-row seat at the 1996 ribbon-cutting ceremony for a new nursery school for children with AIDS that had been reserved for someone who actually had donated money to the school. “I mean, what’s wrong with you, man?” one participant recalled thinking of Mr. Trump. A woman who came through with the money needed by a chess club to travel to a tournament after Mr. Trump skimped out with a $200 donation after seeming to promise far more was reported to have said, “I am ashamed to be the same species as this man.”

The Trump campaign, as has been its wont, sought to counter questions about Mr. Trump’s giving by attacking The Post’s reporting as unfair and inaccurate. Never mind that it failed to respond to 70 questions submitted by The Post in advance of the publication of the most recent article and has been unable to point to any mistakes of fact. As to campaign manager Kellyanne Conway’s blithe assertion to ABC on Sunday that “I’m told by those who are in charge . . . that he’s been incredibly generous with his time and his money over the years,” there is an obvious response: Prove it. All Mr. Trump would have to do is release his tax returns, like every modern major-party presidential nominee before him.