When you look at the short span of President Trump's political career, one question jumps out: How much of his craziest, most paranoid and norm-violating behavior is motivated by a desire to keep his financial arrangements secret?
It began with Trump’s bizarre refusal to release his tax returns, in defiance of both a nearly half-century practice and Trump’s own promise that he’d do so.
Then there was his refusal to divest from his sprawling multinational empire, or even put it into a blind trust -- either of which would have forced at least some information disclosure to a third party.
There were also the interviews and tweetstorms calling journalists who report on his finances "enemies of the people," and suggestions that federal officials who audit him are anti-Christian.
As well as his implicit threat in 2017 that he would fire special counsel Robert Mueller if he crossed a "red line" by examining Trump's personal financial dealings.
Also, his curious personnel priorities. Once it became clear that House Democrats would exercise their explicit statutory authority to get Trump's tax returns from the Internal Revenue Service, Trump asked Senate Majority Leader Mitch McConnell, R-Ky., to prioritize confirmation of Trump's IRS general counsel nominee ahead of confirmation of a new attorney general. This IRS general counsel pick, mind you, also happened to have previously advised the Trump Organization on tax issues.
Trump's treasury secretary has also been spending so much time safeguarding Trump's tax returns, in violation of that explicit statute, that the activity is reportedly crowding out his day job.
All of which raises the question: Why exactly is Trump (and the rest of his administration) expending so much energy and political capital to keep these documents hidden? What could possibly be so disturbing or incriminating to justify such an effort?
One theory is that, maybe, if Trump's tax returns or other financial records become public, his supporters would learn that he's not nearly as rich as he says. Another is that his finances are not exactly on the up and up.
Of course, both explanations could be true.
Thanks to dogged reporting from The New York Times, we know that Trump lost more than $1 billion over a decade beginning in 1985, more than nearly any other taxpayer in the country. We know that he inherited a fortune from his father -- including through legally questionable tax dodges -- but frittered much of that fortune away.
We also know, thanks to other matters of public record -- including testimony from the president's own former attorney, as well as a sworn deposition from Trump himself -- that Trump has inflated his net worth when it suited him.
So yes, whatever information Trump's financial documents reveal about his actual net worth could potentially undermine the core tenet of his sales pitch to his voters.
But what he might be a wee bit more worried about relates to the other red flags raised over the years.
Issues such as: Why international transactions involving multiple Deutsche Bank accounts controlled by Trump set off alerts in a computer system designed to detect money laundering and other financial crimes, as the Times reported Sunday.
Or why Trump purchased a house for $40 million and flipped it for more than twice that amount in a sale to a Russian oligarch, another transaction that might raise suspicions of money laundering.
Or why, about a decade ago, the self-proclaimed "King of Debt" suddenly began making huge, all-cash real estate purchases, including of money-losing golf courses. Debt is highly tax-advantaged in real estate finance. The fact that Trump went on a cash spending spree while interest rates were near zero is fishy at best. Not least because a golf reporter said Trump's son Eric told him that the organization wasn't borrowing from banks because it had "all the funding we need out of Russia." (Eric Trump later denied making the statement.)
We don't know what Trump is working so hard to hide, but we have a lot of hints. They're all troubling. Which is precisely why it's so important that Congress -- as part of its constitutionally mandated oversight duties -- conduct a forensic audit of Trump's worldwide financial dealings. That means learning whom he's been getting money from, whom he owes money to, and what individuals or entities could be using financial influence to exert pressure over policy.
Almost as troubling as whatever it is Trump is trying to hide: Why do all those supposed national security hawks in Trump's party exhibit so little curiosity about the answers?
Catherine Rampell
Catherine Rampell’s email address is crampell@washpost.com. Follow her on Twitter, @crampell.