" The power to pardon is conferred upon the presidency. It is not a personal power of the man or woman who inhabits the office. ... Where a pardon is being used to protect the president personally, or protect the president’s family, friends, or conspirators, it should not be seen as a valid exercise of that constitutional power.

Being able to tell one scenario from the other may not be difficult. Until Trump’s presidency, all recent presidents used a formal process for evaluating and granting pardons. Where pardons are awarded to conspirators of the president, and without any consistent rationale to support them, a court could find the pardon to be an invalid exercise of the power of the presidency. "

― , Where Law Ends: Inside the Mueller Investigation