For more than a year, Donald Trump has said his genius as a businessman makes him uniquely qualified to fix the country’s problems. We can dispense with that fiction now that we know that he claimed a $916 million loss on his 1995 tax returns. Such a mammoth loss amounts to an epic failure, not runaway success.

It is not clear how Mr. Trump racked up this gigantic loss, worth about $1.4 billion in today’s dollars, because he refuses to release his tax returns. It probably had something to do with disastrous business ventures like his bankrupted Atlantic City casinos and the ill-fated acquisition of the Plaza Hotel.

What we do know is that this loss, reported by The Times this weekend, could be used to cancel out taxable income from other sources for up to 18 years, and therefore allow Mr. Trump to get out of paying federal and state taxes. Without more information, we can’t know if he paid nothing in income taxes for nearly two decades, but neither he nor his campaign have denied that he did this.