Donald Trump, challenged again to release his tax returns, offers a nonsense excuse for keeping them secret. But worse than that, the national political reporters covering Trump’s presidential campaign have, yet again, missed big, obvious stories about his conduct and character.

Compounding these errors, some journalists have reported nonsense as egregious as Trump’s, concerning what his tax returns would tell us. Many seem certain that they will reveal his actual wealth even though tax returns measure income, not net worth, as I will explain.

Still, there is plenty we can learn about Trump from his tax returns. Among the big stories the political reporters missed in covering Mitt Romney’s comments about the potential “bombshell” hidden in Trump’s returns — and the former Republican nominee’s ensuing tiff with the potential future nominee:

• How much income tax, if any, Trump has paid over the years, thanks to a special rule enacted by Congress two decades ago that lets full-time real estate professionals live tax-free.
• How much NBC paid him for “The Apprentice,” which would establish whether Trump’s $65 million-per-year claim or NBC’s dismissal of that claim as “grossly inaccurate” is truthful.
• How much, or little, Trump actually gives to charity, a significant issue in light of his claims to be an “ardent philanthropist,” even though his last modest gift to his eponymous foundation was in 2006.
• How much Trump relies on tax-deductible interest to leverage his assets and, thus, how vulnerable he is to pressure from bankers if, as in 1990, he cannot pay his debts as they come due.
• Whether Trump is trying to leverage the IRS to quickly close its current audit, applying the same tactic to limit law enforcement investigations into his conduct that he has wielded ever since he sought his Atlantic City casino license.
• How much of Trump’s lavish lifestyle, which includes being surrounded by bodyguards and flying a Boeing 757 jet, is deducted as business expenses rather than treated as personal after-tax spending.
• The degree to which Trump avoids income taxes by borrowing against his assets to finance his lifestyle, a common tactic among those with wealth that grows faster than their spending.
• Possibly new details on Trump’s business associates and whether he continues his longstanding deals with major mobsters, a major drug dealer (his personal helicopter pilot), and a convicted felon who was his “senior adviser” on some proposed deals.
• How much Trump made off his fraudulent Trump University, which charged up to $35,000 per student for advice you can get at a local newsstand, including Trump’s effort to shut down law enforcement exposing his conduct.

I expect Trump’s returns to be extremely aggressive, but well within the boundaries set by Congress and without even a hint of criminal tax evasion. I also suspect his returns will show negative income. That’s right — negative. The last line on the front page of his Form 1040 likely shows a number less than zero, because of a special tax rule for very rich real estate professionals that I’ll explain below. In essence, that rule means not having to pay income taxes. 

Therein lies the biggest missed opportunity of all for American journalists. If only they would do the work needed to show how our federal tax system actually operates. The awful truth is that Congress burdens most of us with taxes, but for many of the super-rich, including Trump, the income tax system is a massive source of wealth.

By law, billionaire business owners can live free of income taxes if they wish. Every major tax practitioner knows this, as I have explained repeatedly in articles and books going back two decades — and as I will show again now:

Congress requires taxes to be withheld from your pay before you get the residue.

Serious reporting on the Trump tax returns issue would show Americans how Congress lets figures like Trump and Romney delay paying their income taxes for years or decades. These wealthy people receive zero-interest loans from Uncle Sam equal to the taxes they do not have to pay now.

Imagine how rich you would be if all the income taxes withheld from your paycheck — from your first job until your death — were instead available for you to invest. In time, your investments would grow so large that you could voluntarily pay the deferred taxes and still enjoy a fortune several times the sum of those taxes, even after taking inflation into account.

Congress says that Trump and Romney are entitled to zero-interest loans of their taxes. You are not.

Keep in mind: Donald Trump’s tax plan would plunge America deeply into the debt that he claims is such a huge economic threat already, as the conservative (and anti-tax) Tax Foundation has shown. Trump would lavish even more valuable tax cuts on the rich than George W. Bush did, as the highly reliable Tax Policy Center computer model found.

If we had Trump’s complete returns – not just his Form 1040s — we could establish exactly how he would benefit personally from his tax policy proposals, both in his actual financial situation and if he had the same income from work, from non-real estate businesses, from securities investments, or from retirement accounts.

Note to journalists: a 1040 is not a tax return; it’s merely one form. If Trump releases anything but the entire tax returns, the press corps should call him out on it.

It was during an appearance on Fox News, that Romney warned of a “bombshell” in Donald Trump’s tax returns:

“I think there’s something there. Either he’s not anywhere near as wealthy as he says he is or he hasn’t been paying the kind of taxes we would expect him to pay, or perhaps he hasn’t been giving money to the vets or to the disabled like he’s been telling us he’s doing.”

When Trump said he couldn’t release his returns because of a routine audit, Romney called him out, tweeting:

No legit reason ‪@realDonaldTrump‬‬‬ can’t release returns while being audited, but if scared, release earlier returns no longer under audit.

The Romney-Trump controversy created what journalists call a “news peg,” or a reason to write about an issue.

But the biggest issue still not getting covered is that Congress has created two tax systems, separate and unequal. One is for workers, who are efficiently and thoroughly taxed with only minor opportunities to cheat. The other is for real estate professionals (Trump), private equity managers (Romney), hedge fund managers, and other highly paid executives, athletes, and entertainers, for whom Congress converts the burden of taxes into a profitable investment by permitting delayed payment.

Romney is right that there is no legal reason for Trump to keep a tax return secret, even if the IRS is auditing his 2011 through 2014 returns. Significantly, Trump called this procedure a “routine audit,” undercutting his rationale for not disclosing those returns.

One of the few journalists to get that right is Kelly Phillips Erb, a tax lawyer who writes a Forbes column. She notes that there are political, but not legal, reasons to withhold the tax returns. Chris Isidore of CNN Money also got it right (citing me as a source).

Releasing the tax returns will not tell the IRS anything it does not already know. And if his returns are honest then, at most, the IRS will dispute such matters as the timing of deductions, not their legitimacy. If that happens I would be the first to say his returns are clean, just as I have said about Dick Cheney’s.

You might expect that the right-wing opinion journalists who champion the interests of the rich and dismiss concerns about America’s extreme inequality would display some informed knowledge about the intersection of personal finance and taxes in writing about the Trump tax returns. You might think that, but you would be wrong.

A good example of the know-nothing journalism is the most recent offering by Jim Geraghty, who writes in National Review that Trump’s tax return will tell us how rich he is, citing a handful of clips.

Geraghty wrote, “If Trump’s fortune is multiple billions as he contends, one or two tax returns would have demonstrated the three sources [who claimed otherwise] were wildly off-base.” But Geraghty is wrong. Tax returns tell us about what Congress requires taxpayers to report as income, but not about their wealth. Trump’s returns might tell us something about the actual scope of his wealth, however, depending on how much of it is from depreciable assets.

Warren Buffett demonstrated how this worked in 2010, so it is not something that only a tax policy expert can understand (or that journalists couldn’t learn before writing). Buffett disclosed in a letter to a Republican Congressman that his 2010 tax return showed income of $62,855,038. Now that is a lot of money, more than the average American taxpayer would have reported after living for 1,110 years.

That year, Forbes Magazine estimated Buffett’s net worth at $50 billion, based on his Berkshire-Hathaway shares which, significantly, do not pay dividends and none of which Buffett has ever sold. He has given many shares away.

Buffett is much richer than Forbes reported, owing to other investments, but we do not know his actual net worth. And even if Buffett released his tax returns we would not know.

The income that Congress required Buffett to report equaled a bit more than a tenth of one percent of his wealth. Had he chosen to do so, however, Buffett could have legally lived tax-free by borrowing against his assets because Congress has decreed that borrowing is not a taxable event. Donald Trump’s tax returns, if we had all of them, may tell us how much he has used borrowing to avoid taxes.

I revealed Trump’s income and tax payments from his early years in my book Temples of Chance. In 1977 he made $118,530 and paid $42,386. The next year Trump reported an income of negative $406,379 and paid nothing. In 1979 he reported negative $3.4 million and again paid no taxes.

No doubt that reflects what Romney hinted: Trump may well report negative income and live tax-free, an issue the mogul and I once discussed at the old Trump Castle Casino in Atlantic City. (Incidentally my employer, then The Philadelphia Inquirer, paid for my lunch.)

Trump seemed to want to interfere with the IRS audit when he tweeted: “As far as my return, I want to file it. I will absolutely give my return but I’m being audited now.”

Asking the IRS to close the audit or face criticism seems innocuous, unless you understand what is going on politically with tax law enforcement.

Congressional Republicans, sometimes with the acquiescence of President Obama, have cut the IRS budget so severely that its computer systems are starting to fail and its capacity to pursue major tax cheats is drying up from a political El Niño. Yet wage earners are still being fully taxed. Thanks to shoddy reporting, most Americans believe the IRS “targeted” conservative groups seeking to influence elections — the so-called C4 organizations — giving Congress an excuse to cut the IRS budget. In fact, a mid-level manager in Kentucky who is a self-described conservative Republican ordered the focus on C-4 groups. And the documents show he was doing his duty because many of the C4 applications stated that the groups were partisan, which Congress has made a no-no for tax exemption.

Trump’s IRS tweet was part of a pattern. He only got his Atlantic City casino license because he somehow persuaded the New Jersey Division of Gaming Enforcement to limit its inquiry into his background. Had Trump not succeeded he would not have been found eligible for a license because he concealed that he was the target of a bribery investigation, an issue outlined in items 13 and 14 of my 21 Questions for Donald Trump. Lower-level employees were denied licenses over much smaller matters.

Consider the contrast between Trump seeking to shield himself from law enforcement and his plans for harsh treatment of those who protest his proposals (including suggesting they be beaten up), his plan to send armed federal agents into millions of homes to find suspected illegal residents, and his plans to bar Muslims from entering the country, evidently including currently serving soldiers and sailors.

Trump should release his tax returns – not just a few but at least those since 1988, when he sought the vice presidential nomination that went to Dan Quayle of “potatoe” fame.

Dozens of tax returns by Presidents and candidates back to Franklin D. Roosevelt are available here thanks to historian Joseph J. Thorndike and Tax Analysts (for which I write columns on taxes).

Every return Hillary Clinton has signed since 1992, in full, is there to read, including her 2014 return showing the Clintons made almost $28 million that year, while giving more than a tenth of those earnings to the Clinton Family Foundation.

Since there is no legal reason to hide his tax returns, and since Trump wants to make a major change in our tax system that analysis shows would shower favors on people like himself, and since he has a long history of trying to restrict law enforcement inquiries into his conduct: Why aren’t we seeing gaggles of reporters demanding answers from him?

The reason is that Trump keeps journalists in a fenced-off corral, to make sure no one can ask a question he does not expect. Think about that in terms of accountability if Trump were to become president.

But the equally important issue that Romney, of all people, has opened the door to examining is how our federal tax system takes from the many while enriching a select few.

Why has not one presidential debate questioner asked about the tax system? Why is this inequity not a Page One story in every paper in America? Why is this sore topic never mentioned on the nightly network newscasts? Why do politicians left and right nearly all avoid this issue?

Where are the editorials calling for hearings and naming the politicians who (often unknowingly) voted to create this system of redistribution for the richest of the rich?

Oh, I forgot, it takes a lot of work to understand our tax code and then translate how it works in plain English. And why do the work at reporting when Trump will say wild, baseless, and sometimes crazy things that fascinate big audiences, regardless of whether they are applauding or appalled?

Why risk criticism for doing what should be the routine work of trying to make a politician accountable, especially when journalists win so many rewards for the easy job of glitz-mongering?

If you want to understand these issues in depth read my books Perfectly Legal, Free Lunch, and The Fine Print; this cover story I wrote for Newsweek ,and my Tax Analysts columns (paywall for most) including this one outside the paywall headlined “Master Limited Partnerships: Paying Other People’s Taxes.”

Photo: Marco Rubio and Donald Trump react to each other as they discuss an issue during the debate sponsored by CNN for the 2016 Republican U.S. presidential candidates in Houston, Texas, February 25, 2016. REUTERS/Mike Stone