The pantheon of problematic presidential pardons has always cut across partisan lines. Former President Joe Biden’s pre-emptive pardon of his son, Hunter Biden, was among the most brazen examples ever of a president putting family loyalty above presidential duty. Barack Obama’s commutation of the prison sentence of Army private and document-leaker Chelsea Manning was widely condemned as a live threat to national security. Bill Clinton’s pardon of major Democratic donor Marc Green was so suspect that it spawned a federal investigation. As is so often the case in the Trump era, our current president has managed to take one of...