It is very simple to have Trump remove himself from the presidency. It requires neither impeachment nor a finding of incapacity by the cabinet.

Indeed, it takes only one house of Congress, (perhaps only one committee?).

Subpoena his taxes.

I predicted early on that Trump would never, ever, under any condition, reveal his tax returns. His whole psychological edifice is based on his brand. Let’s face it: what kind of moron sues for defamation because someone says his net worth is not X? (During the deposition in that case, Trump claimed his “brand’s value” was “based on how he was feeling that day”).

His tax returns would reveal the truth. Resigning the presidency “on principle”, as he would spin it, is far less of an existential threat to his psyche than for the world to discover the narcissist’s true net worth.

If either the House Committee on Oversight and Government Reform, chaired by Jason Chaffetz (R-UT), or the Senate Homeland Security and Governmental Affairs Committee, chaired by Rob Johnson (R-WI), were to open an investigation into Trump’s likely abundant conflicts-of-interest, illegal leasehold, and emoluments clause violations, it would be impossible to do so without the tax returns.

Trump, of course, would fight the subpoenas, but he would have little chance of prevailing in court. Once the final determination were made that he had to produce his tax returns, Trump would resign the office, uttering some psychobabble about his belief in the Constitution (that he shows few signs of having read nor caring that he hasn’t read it) and right to privacy.