Tuesday night, Donald Trump and Joe Biden square off at Case Western University for the first of three presidential debates. Host Chris Wallace of Fox News has already indicated that topics will include such mainstays as election integrity, the Supreme Court and the coronavirus pandemic. But noticeably missing is the subject of taxes, and while that might have seemed a reasonable omission last week, The New York Times just changed all that. The newspaper’s scoop on how President Trump has avoided paying so much for so long — contributing nothing to Uncle Sam for 10 of the last 15 years — raises questions about the president’s integrity, but more basically about a U.S. tax system that could possibly allow a scenario in which the star of “The Apprentice” and owner of a real estate empire could pay less in taxes than your basic summer intern.

Granted, we have low expectations for the debates. Name-calling, taunting and outright fabrication were Mr. Trump’s preferred techniques in 2016, so it’s hardly a stretch to expect a similar approach in Cleveland, and again on Oct. 15 in Miami and one week later in Nashville. And, unfortunately, Mr. Wallace has indicated he will not be fact checking the candidates. So if some equivalent moment arises to Mr. Trump’s accusation that Ted Cruz’s father was involved in the John F. Kennedy assassination, it’s up to Mr. Biden alone to correct him. As Mr. Biden recently noted, Mr. Trump’s best argument is “made in urine” — a reference to the president’s odd demand that the former vice president submit to a drug test.

If Americans can get past the sheer fakery documented by the Times’ reporting of Mr. Trump’s tax filings — the financial records strongly suggest his financial acumen is illusory, and his singular gift is for self-promotion and accruing debt — there are also some important tax policy choices to be discussed. If there is one overarching issue that’s been amplified by the events of 2020, it is economic inequity. It’s what links the urban unrest, the spread of COVID-19 (which disproportionately endangers low-income and minority communities), the economic downturn and on and on. Here are the undisputed facts: Over the last half-century, the top-earning 20% of U.S. households have steadily amassed a larger share of the nation’s income to the point where it’s now more than all of the lower four-fifths combined. That’s the worst imbalance of all of the G7 nations and it’s not gone unnoticed: a Pew Research Center survey found 61% of Americans think there’s too great an imbalance. And that was as of one year ago. The pandemic has made matters worse.

So how does a country end up moving in this self-destructive direction? One way is to pass tax cuts that disproportionately benefit the rich, as President Trump did in 2017, the legislation having provided 65% of its financial benefit to the highest earning 20%. And then, adding insult to injury, the perpetrator would — as he paid $750 in total federal taxes that year, according to the Times — claim any plan to more appropriately tax the wealthy would amount to socialism or perhaps communism. And this remains the recurring theme in the president’s conversations about the U.S. economy even as the deficit rises to historic heights and the day of reckoning when someone, perhaps his successor, is forced to both cut spending and raise taxes to somehow wrestle a $26 trillion imbalance into control.

There’s little doubt that Mr. Trump’s most ardent supporters will dismiss these latest disclosures as “fake news,” the candidate’s favorite term for information that portrays him in a negative light regardless of accuracy. But surely, at some point, people are going to wake up and recognize that all of these distractions — from stirring up his political base of abortion opponents with Supreme Court nomination fights to posing as the “law and order” president who wants to lock up urban protesters — are, like his house-of-cards business empire, mostly done for show. At his heart, Mr. Trump has been running a con. His lies point to it. His behavior confirms it. And now the numbers leave little doubt.