From the abstract for Aaron Rappaport, An Unappreciated Constraint on the President’s Pardon Power (Nov. 30, 2018):
Most commentators assume that, except for the few textual limitations mentioned in the U.S. Constitution, the President’s pardon power is effectively unlimited. This paper suggests that this common view is mistaken in at least one unexpected way: Presidential pardons must satisfy a specificity requirement. That is, to be valid, the pardon must list the specific crimes insulated from criminal liability.
This claim bears a significant burden of persuasion, since it runs so counter to accepted opinion. Nonetheless, that burden can be met. The paper’s argument rests on an originalist understanding of the Constitution’s text, an approach that leaves little doubt that a specificity requirement is an implicit limitation on the President’s pardon power. It also demonstrates that the main objections to the argument – that the requirement runs contrary to the Constitutional text or historical practice – are misguided and unpersuasive.
Of course, even if a specificity requirement exists, one may wonder about its significance. After all, the requirement does not prevent a President from issuing a pardon to any person or for any crime. Nonetheless, as the paper explains, a specificity requirement may prove more powerful than it first appears. Most importantly, it both limits the scope and raises the cost of issuing pardons for criminal violations, including violations of the electoral process. In so doing, the specificity requirement serves as an unexpected ally in the fight for political accountability and in defense of the rule of law.