AND THERE'S NO SUCH THING AS LUCK:

The latest revelations, in an article published by The New York Times, make a "compelling" case for more disclosure, said Michael Knoll, professor of law and real estate at the University of Pennsylvania Law School. "If his loss was so massive that he didn't pay federal income tax for 15 to 20 years, that's surprising. It's even more surprising that someone in that situation would run for president."

Even if Mr. Trump was correct when he asserted that he only took advantage of what the law allows, such a huge loss undermines one of his central campaign themes, which is that he is an astute and successful businessman.

Given the size of the loss that Mr. Trump reported, "it's clear he was a spectacularly disastrous businessman," Mr. Rosenthal said.

Douglas Holtz-Eakin, an economist who served as director of the Congressional Budget Office and is now president of the American Action Forum, a conservative pro-growth advocacy group, agreed: "It's either a unique combination of bad luck or he's a terrible businessman or both. I don't understand how you can lose a billion dollars and stay in business."

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