In all such instances, however, the president is acting as a kind of super-judge and making a decision about someone else’s conduct, the justice of someone else’s sentence or whether it is in the national interest to prosecute someone else. He is not making a decision about himself.
Self-pardon under this rubric is impossible. The foundational case in the Anglo-American legal tradition is Thomas Bonham v. College of Physicians, commonly known as Dr. Bonham’s Case. In 1610, the Court of Common Pleas determined that the College of Physicians could not act as a court and a litigant in the same case. The college’s royal charter had given it the authority to punish individuals who practiced without a license. However, the court held that it was impermissible for the college to receive a fine that it had the power to inflict: “One cannot be Judge and attorney for any of the parties.”