EveryCRSReport: Presidential Pardons: Overview and Selected Legal Issues,, January 14, 2020: “Article II, Section 2 of the U.S. Constitution authorizes the President “to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.” The power has its roots in the king’s prerogative to grant mercy under early English law, which later traveled across the Atlantic Ocean to the American colonies. The Supreme Court has recognized that the authority vested by the Constitution in the President is quite broad, describing it as “plenary,” discretionary, and largely not subject to legislative modification. Nonetheless, there are two textual limitations on the pardon power’s exercise: first, the President may grant pardons only for federal criminal offenses, and second, impeachment convictions are not pardonable. The Court has also recognized some other narrow restraints, including that a pardon cannot be issued to cover crimes prior to commission. The pardon power authorizes the President to grant several forms of relief from criminal punishment. The most common forms of relief are full pardons (for individuals) and amnesties (for groups of people), which completely obviate the punishment for a committed or charged federal criminal offense, and commutations, which reduce the penalties associated with convictions. An administrative process has been established through the Department of Justice’s Office of the Pardon Attorney for submitting and evaluating requests for these and other forms of clemency, though the process and regulations governing it are merely advisory and do not affect the President’s ultimate authority to grant relief.
As for whether a President may grant a self-pardon, no past President has ever issued such a pardon. As a consequence, no federal court has addressed the matter. That said, several Presidents have considered the proposition of a self-pardon, and scholars have reached differing conclusions on whether such an action would be permissible based on the text, structure, and history of the Constitution. Ultimately, given the limited authority available, the constitutionality of a self-pardon is unclear…”