When Roger Stone was sentenced to 40 months in federal prison for obstruction, making false statements, and witness tampering, Judge Amy Berman Jackson concluded, “He was not prosecuted, as some have complained, for standing up for the president. He was prosecuted for covering up for the president.” Stone was scheduled to be incarcerated on July 14, 2020. On July 10, Donald Trump commuted his sentence. Is this particular use of the president’s power constitutional and lawful? Many in the legal establishment maintain that it is, but we disagree.

The power to grant “pardons and reprieves” includes the power to commute, or reduce, sentences after convictions. But this power is constrained by a limit: “except in cases of impeachment.” Traditionally, this exception has been read to mean only that a president cannot use the pardon and reprieve power to prevent or undo an impeachment by the House or an impeachment conviction by the Senate. By this interpretation, only impeachment charges themselves are precluded from presidential pardons. (According to the Constitution, the vice president and “all civil Officers of the United States” are subject to impeachment, which means, for example, that a president cannot pardon a federal judge’s impeachment.)

Källa: The Traditional Interpretation of the Pardon Power Is Wrong