In stark contrast, Trump waived his privileges and made his lawyer available for 30 hours of questioning. Consequently, the special counsel has already gotten far more information than he was entitled to regarding the president’s actions and state of mind. Bear in mind, due to the Fifth Amendment privilege against self-incrimination, it is very common for prosecutors to complete investigations and make charging decisions without interviewing the principal subject of the investigation. And the prosecutor almost never gets to interview the subject’s lawyer.

Plainly, the special counsel has all the information he needs to write his report. The president could well decide to consent to Mueller’s request for an interview. As we’ve observed, there would be risk in doing so; the president would be well advised to decline unless, at a minimum, Mueller discloses whether he regards the president as a criminal suspect and, if so, of what crime and on what basis. But the prospect of a subpoena should be off the table. The special counsel does not need the president’s testimony in order to complete his work.