But the president has an option that no one has suggested. He knows better than anyone whether he is vulnerable to prosecution, and more than anyone else he wants to bring this matter to a close and get on with his presidency. Trump could tell Mueller that he will not appear before a grand jury. He could argue that, as the apparent target of the special counsel, he cannot be compelled to testify.

Whether defendants have this option is debatable among lawyers, but as a political matter most Americans would think it’s unfair to call the president to testify when the prosecutor in this case has had a year to develop his case. If he does not have a case without the president’s testimony, then he should give up.

Accordingly, Trump could tell Mueller — perhaps, fittingly, in a tweet — “I will not sit down with you and answer your questions. Nor will I respond to a subpoena to appear before a grand jury. Instead, if you actually have evidence of my wrongdoing, which I don’t believe, I urge you to bring it to the grand jury and indict me. I’ll see you in court.”