Although our government is said to be one of checks and balances, the president’s power “to grant Reprieves and Pardons for Offenses against the United States” appears to be unlimited. In granting this power, the Framers deliberately cast structural safeguards aside. Nevertheless, the presidency of Donald Trump prompted a search for limits. This Article examines: (1) whether a president may pardon crimes that have not yet happened (or announce his intention to do so); (2) whether he may pardon himself; (3) whether he may use pardons to obstruct justice or commit other crimes; (4) whether criminal statutes should be construed not to apply to the president when they arguably limit the pardon power; (5) whether the Take Care Clause limits the pardon power; (6) whether pardons can deprive victims of due process; (7) whether pardons ever violate the separation of powers by limiting the authority of courts; (8) whether the exception to the pardon power for impeachment cases does more than prevent the president from blocking the impeachment of federal officeholders; (9) whether pardons must specifically identify the crimes pardoned; and (10) whether pardons are invalid when issued as the result of fraud, bribery, or other unlawful conduct. Applying common-law principles that have limited the pardon power from the start, the Article explains why the pardons President Trump granted Roger Stone and Paul Manafort are invalid and why the Justice Department could seek a declaratory judgment saying so.