In Schick v. Reed, the U.S. Supreme Court ruled in 1974 that the President has the power to condition a pardon on any reasonable conditions related to rehabilitation and deterrence of future criminal conduct. The case involved Mauro DePasquale, who was convicted for murder and sentenced to death by court-martial during World War II but had his sentence commuted by President Eisenhower with a condition that he would never be eligible for parole. After serving more than two decades in prison, DePasquale challenged this restriction as unconstitutional under due process grounds arguing it exceeded presidential authority because it imposed punishment beyond what courts could impose. The Supreme Court disagreed holding that while Congress sets penalties for crimes including eligibility for parole, once conviction occurs and sentence is affirmed on appeal, executive clemency comes into play which includes pardons with conditions attached by Presidents over history reflecting an amalgam of considerations both public and personal. Therefore, when granted a conditional pardon reducing his death penalty to life imprisonment without possibility of parole - even though federal law otherwise provided such opportunity - DePasquale accepted knowing its terms thus cannot challenge its validity later.

In the dissenting opinion for Schick v. Reed, Justice Marshall argued that the President's power to commute sentences should not extend to imposing conditions that are otherwise unconstitutional or illegal. He contended that allowing such a practice would effectively give the executive branch legislative powers, which is contrary to the separation of powers principle in U.S. Constitution. Furthermore, he expressed concern about potential abuses of this power and noted there were no checks on it if used improperly. In his view, while commutation can be an act of mercy and leniency by reducing punishment severity, adding conditions like mandatory life parole could actually make a sentence more severe than originally imposed by court - something he believed was beyond presidential authority.