By Frank Bowman

Rudolph Giuliani, the newest in the revolving cast of Mr. Trump’s lawyers, has made a number of striking legal claims in his short tenure.  His latest is that Mr. Trump is not obliged to comply with a subpoena to testify from a court or grand jury.

Giuliani is assuredly wrong.  But any attempt to subpoena Mr. Trump would raise a number of complicated issues.

First, Giuliani is right that Mr. Trump, like any other person, has a right under the Fifth Amendment to decline to answer questions that may tend to incriminate him.  However, that right does not allow Trump or anyone else to simply refuse to appear in a court or grand jury room if properly subpoenaed.  Rather, a person subject to subpoena must appear at the date and time specified in the subpoena and assert the privilege to particular questions.

If a witness is technically a “target” of a grand jury investigation and provides the prosecution with a written statement of intention to assert the Fifth Amendment, DOJ policy is that such a witness “ordinarily should be excused from testifying.”  U.S. Attorney’s Manual, 9-11.154 . But that would be a matter of discretion, not law.  And even in that case, unless the witness is expressing an intention to assert the Fifth as to all questions, he would ordinarily be obliged to appear and answer questions that cannot be reasonably viewed as seeking self-incriminatory information.

In the case of a president, even one who is not formally a “target,” the prosecutor might accommodate the president’s expressed intention not to answer questions on particular topics that seem plainly incriminatory by agreeing in advance not to ask them.  But that, too, would be a matter of discretion rather than law.

In any case, it seems somewhat unlikely that even this unconventional president would want to be seen as formally “taking the Fifth” to avoid testifying.

Second, there are issues about which Mr. Trump might claim some form of “executive privilege.”  Broadly speaking, executive privilege is the claim that a president can withhold information from congress, the courts, or the public for reasons relating to the proper functioning of the presidential office.  Legitimate claims of executive privilege are generally related to national security or protecting the privacy of White House deliberations for reasons promoting the public interest.

A great many questions Mueller is said to be interested in asking cannot by any reasonable stretch of the imagination fall within the executive privilege doctrine. Virtually all the questions on the list published by the New York Times that relate to Russia seem far outside any reasonable executive privilege claim.  Leaving all other considerations aside, almost all of them relate to events that occurred before Mr. Trump took office.

Some questions Mueller might ask would probably draw objections on executive privilege grounds.  For example, questions about conversations between Mr. Trump and White House advisers about whether to fire former FBI Director James Comey would probably draw such objections on the theory that executive branch personnel decisions should ordinarily remain private.  Mr. Mueller’s team might respond that executive privilege, to the extent it exists, must yield when the inquiry is into possible criminal misuse of the presidential power being discussed.  The analogy would be to the crime-fraud exception to the attorney-client and marital privileges, pursuant to which otherwise confidential communications must be disclosed if they were in furtherance of crime.

The Supreme Court held in U.S. v. Nixon that claims of executive privilege must yield in the face of investigation of criminal wrongdoing by the president or his aides. Nonetheless, Mueller’s people would have to make more than a bare claim of investigative interest to succeed in compelling testimony from this or any president about internal deliberations on policy or personnel decisions.

Finally, one argument that has been floated in the wake of Giuliani’s comments is that the president need not comply with a subpoena because he is the head of the executive branch and thus the ultimate boss of the prosecutors running the Mueller investigation.  This is frivolous. A subpoena is not a request by a prosecutor.  It is an order issued by authority of the court (if a trial subpoena) or of the court and the grand jury (if a grand jury subpoena).  It is a command by the judicial branch.  And it is not one that a president is entitled to disobey.

My personal bet is that Mr. Trump will not agree to testify voluntarily, and that Mueller’s team will subpoena him as a last resort.  Should that come to pass, it will get interesting very fast.