If Trump is so ‘smart’, why can't he see the blindingly obvious when it comes to his murky tax affairs?

There are good reasons why presidential candidates have for three decades voluntarily offered up their tax affairs, and why congress should maintain constant vigilance towards the executive and its private financial activities

So now we know why Donald Trump has been so cagey about his tax returns. Partial versions of these dating from 1985 to 1994 have been obtained and published by The New York Times. They show that Mr Trump, then a property developer, amassed losses of some $1.17bn over that decade. Substantial by any standards, they were by far the largest registered by the Inland Revenue Service for any American taxpayer in the period.

Mr Trump claims, with some plausibility, that they were tax losses, used for reducing his bills from the IRS. Such techniques are certainly commonplace in the real estate world and elsewhere. However, the sheer scale of the losses, their persistence and the lack of evidence for the profits they were supposed to cover raise questions about just how robust Mr Trump’s businesses were during the Reagan and Clinton years. We already know that his plans for casinos and an airline came to little.

That Mr Trump will have paid little or no federal tax doesn’t come as much of a surprise. During the 2016 campaign it emerged, from local financial filings related to Mr Trump’s application to open a casino, that he had indeed paid no income tax for a period of some years.

Hillary Clinton brandished the revelation like a lethal weapon; Mr Trump dismissed it with a characteristic quip during a presidential debate: “That makes me smart.” Yet if that does make him look smart, and proves the point, why has Mr Trump been so unwilling to boast about the facts before now? And, intriguingly, who or what provided the funds that allowed Mr Trump’s businesses to keep functioning as the losses piled up?

Whatever Mr Trump was up to long ago – and he denies the story, describing it as “demonstrably false” and “highly inaccurate” – his more recent tax affairs remain a mystery, and one of more immediate concern. The US treasury secretary, Steve Mnuchin, has refused to allow congress access to Mr Trump’s tax records via an IRS disclosure.

Mr Trump and his lawyers have said the president will never disclose the information himself. Congress (in reality the Democrats) is set to issue a subpoena requiring the IRS to send it the documents, as the law allows; the IRS says it will publish its existing legal counsel and will probably appeal against the subpoena. It will be a long, drawn-out process, and it is perfectly possible, as is the way with such wrangles, that Mr Trump’s tax returns won’t see the light of day before the 2020 presidential election.

Congress, though, is right to pursue the matter. America has never had a richer man in the White House (if indeed he is as rich as he claims – $10bn, he says), and congress and the American people have a right to know about conflicts of interest relating to Mr Trump’s financial affairs, now or in the past.

The relevant legislation was passed as long ago as 1924, after the Teapot Dome scandal. Though comically named, it was one of the worst high-level cases of corruption in US history, and it led to a prison sentence for the interior secretary for taking bribes in return for concessions to oil companies.

No one is suggesting that the president or his cabinet have indulged in such things, but there are good reasons why presidential candidates have for three decades voluntarily offered up their tax affairs, and why congress should maintain constant vigilance towards the executive and its private financial activities. If senior figures are suffering, or have suffered, substantial financial losses that potentially place them in thrall to third parties, it is common sense to want to clarify that.

Mr Trump will, sooner or later, one way or another, see the rest of his tax affairs enter the public domain, for good or ill. If, as he insists, they will merely show how “smart” he is, he may as well turn them over now.