It is conceivable that McGahn could resist the interviews by drawing on the constitutional theory that Trump’s lawyers have been testing publicly—that there is no “evidence” for him to give because the case for which it is sought, presidential obstruction of justice, is constitutionally impermissible. This maneuver would stand little chance of success. Assuming that McGahn were willing to be the vehicle for a test of Trump’s constitutional theory, he would have reason to doubt that he would prevail. A court would likely hold that the constitutional question was premature and not one for him to raise, and that at this stage of the proceeding, he must give testimony.

The entire episode serves yet again of a reminder of the potential hazards that accompany the benefits to the president of the institutionalized office of the White house counsel. The president has ready at hand in the West Wing dedicated counsel on a range of issues who can also serve as a force for channeling the legal resources throughout the executive branch in support of administration policies. In this respect, the counsel is truly, as often described, the “president’s lawyer.” But the counsel is not the “president’s lawyer” in the way that Trump apparently imagined that those lawyers he hired in the private sector were “his lawyers.” This is the irony of the counsel’s position: the very proximity to the Oval Office that distinguishes the role and accounts for so much of its value, can also present grave risks for a president in legal trouble.