For this so-called law professor to opine that the exercise of a constitutionally defined power of the office of president would be an affront to the Constitution shows that the man is ill-informed and unqualified to instruct others.  There is but a single exception to the ability of a president to pardon an offense against the United States, impeachment, and Sheriff Arapio wasn't impeached.  That's where the legal discussion begins and ends. It would appear that the concept of three separate and co-equal branches of government is one which this unqualified professor is unable to grasp or is willfully overlooking in pursuit of his political activism.