Financial sophisticates know and explain how complicated all this is. Mr. Trump can’t establish a blind trust because blind trusts normally consist of stocks, bonds—liquid assets. Mr. Trump’s wealth is in famous entities, in his brand. He knows where his buildings are, his past and current deals are.

He said when campaigning that if elected he’d turn the business over to his children. But that would require never talking to them about matters touching on the central family ethos: money, profit, the deal.

The editorial page of this newspaper offered a sound though difficult route: Mr. Trump should liquidate his stake in his company and put the proceeds in a true blind trust, in which the Trump children keep the assets in their name. He can “transfer more to them as long as he pays a hefty gift tax.” A fire sale on real estate would no doubt be seized upon by buyers like Donald Trump—people looking for the greatest asset at the lowest price. But it’s hard to see how any other plan would help Mr. Trump avoid endless accusations that he is enriching himself as president, that he is, in fact, a dopey kleptocrat who can’t help doing what he does.

It would be a painful act, selling the business he loves and around which he has ordered his life. But there would be comfort in this: In doing the right thing, in denying his opponents a sword, in enhancing his stature and demonstrating that yes, he will sacrifice for his country.