In both Monday's debate and since, the campaign has offered an at-times-brazen and sometimes-more-diplomatic defense: It's just "smart."
Here's the campaign's statement on Saturday night: “Mr. Trump is a highly-skilled businessman who has a fiduciary responsibility to his business, his family and his employees to pay no more tax than legally required. That being said, Mr. Trump has paid hundreds of millions of dollars in property taxes, sales and excise taxes, real estate taxes, city taxes, state taxes, employee taxes and federal taxes, along with very substantial charitable contributions."
Key line: "No more tax than legally required." Nobody is accusing Trump of doing anything illegal by avoiding income taxes — there are ways for real estate moguls to do it — but, politically speaking, a billionaire not paying income taxes for years or even decades could rub voters the wrong way.
What's more, the campaign emphasizes all the other taxes Trump has paid — the argument apparently being, 'Even if he didn't pay income taxes, he still paid taxes.'
Then Trump tweeted the following Sunday morning:
The tweet sounds a lot like the less-refined argument Trump made at Monday's debate and subsequently, arguing that not paying taxes makes him "smart."
"I never said I didn't pay taxes," Trump maintained. "[Hillary Clinton] said, 'Maybe you didn't pay taxes.' And I said, 'Well, that would make me smart,' because tax is a big payment. But a lot of people say, 'That's the kind of thinking that I want running this nation.'
"Some people loved that statement, and other people didn't. But the fact is that I think people are looking at it like maybe that's the kind of person we need. ... I think that's the kind of thinking we need in our country."
One big problem with Trump's comments on Wednesday is that there was a record of him paying no or very little income taxes — even before the Times report Saturday night. Of the five years for which we have Trump's tax records, he didn't pay any or nearly any taxes. So for him to suggest that he hasn't avoided paying income taxes at some point is disingenuous, at best.
A second problem is that he did appear to say Monday night that his past avoidance of income taxes was "smart." Here's the exchange:
CLINTON: Or maybe [the reason Trump doesn't release his tax returns is that] he doesn't want the American people, all of you watching tonight, to know that he's paid nothing in federal taxes, because the only years that anybody's ever seen were a couple of years when he had to turn them over to state authorities when he was trying to get a casino license, and they showed he didn't pay any federal income tax.
TRUMP: That makes me smart.
Clinton's remark was clearly about instances in which Trump didn't pay much or any income taxes, and he cast it as being "smart." Trump argued Wednesday that he never said he didn't pay income taxes, but there is clearly evidence that he hasn't — at least for the handful of years for which we have evidence.
Trump is clearly digging in here — relying on a long-standing strategy in which he makes the case that he was a skilled player at an unholy game and that the country needs someone smart enough to game the system as president. He makes the same case about his campaign contributions to Democrats like Clinton.
But to this point, he conspicuously has avoided the opportunity to say whether he has evaded paying income tax, apart from the few years for which we have evidence that he did indeed avoid paying them.
And everything he and his campaign say sounds like they know the truth may continue to seep out — as it did with the Times report.