The use of the autopen, a device that reproduces signatures and is ubiquitous in government and business, is ordinarily uncontroversial. There is no power to undo a pardon in the Constitution or case law.

President Donald Trump suggested Monday that the legality of autopen-signed pardons should be decided by the courts, questioning whether former President Joe Biden’s final clemency orders, including controversial preemptive pardons,

Donald Trump says Joe Biden's last-minutes pardons via autopen are null and void. But what is an autopen? And what does it mean for pardons?