Presidents have the power to pardon anyone they see fit:
Article II, Section 2 of the U.S. Constitution gives the president "Power to grant reprieves and pardons for offenses against the United States, except in cases of impeachment." A reprieve reduces the severity of a punishment without removing the guilt of the person reprieved. A pardon removes both punishment and guilt.
The question that Pardon Power discussed back in December was can a president revoke his own – or another president’s – pardon?
This has actually happened – Grant revoked some of Andrew Johnson’s pardons:
Ulysses S. Grant's first clemency decision, on his third day in office, was to revoke two pardons granted by Andrew Johnson. Both men challenged Grant's power to do so, and lost their case in federal court. A central passage in a judicial opinion read:
If the president can arrest the mission of the messenger went the messenger hasThe fact that "the president" - in this case - meant two different presidents (Johnson and Grant), and the fact that - in this case - the warden had actually received the pardons but simply stuck them in his desk for a while, did not matter. The pardons had not actually been placed in the hands of Moses and Jacob DePuy, so the two men stayed in prison and were pardoned (by Grant) later.
departed but ten feet from the door of the presidential mansion, he can arrest
such mission at any time before the messenger delivers the pardon to the warden
of the prison.
Grant also revoked the pardon of James F. Martin, but the New York Times, reported that the official order from the State Department reached the U.S. Marshal in Massachusetts "too late." That is to say, Martin had accepted his pardon and had exited the premises. No effort was made to put him back.
Finally Grant revoked the pardon of Richard C. Enright, who was sentenced to 18 months in prison and fined $2,500 for conspiracy to defraud the government. Johnson granted a full pardon 12 months into the sentence but, before the pardon could reach Enright's hands, Grant revoked it. Enright had to cool his heels another 8 months.
Pardon Power also tells us that presidents have even revoked their own pardons (I've picked a few from Pardon Power's more conprehensive list)!
- The November 11, 1862 clemency warrant granting a "full unconditional pardon" to James J. Palmer was "returned" and "not put into effect." It appears Abraham Lincon never re-issued the pardon to Palmer.
- Rutherford B. Hayes cancelled the pardon that he had granted to Mollie Harris on July 27, 1878. He then granted the pardon to Mollie the same day!
- Chester Arthur cancelled his November 25, 1881, pardon of Illinois counterfeiter John Boatright. Boatright was then pardoned by Arthur again on December 9, 1881.
- On September 19, 1889, Benjamin Harrison cancelled the commutation of Benjamin Watson. The commutation was re-issued on October 19.
- On February 6, 1925, Calvin Coolidge cancelled the commutation of Harry S. Stout's sentence "before delivery." It does not appear that the commutation was ever re-issued.
So from these historical examples we can see that it is possible for one president to revoke another’s pardon just as it is possible to revoke their own.