From The Nation:
A pardon for Roger Stone would be the capstone of the White House’s extraordinary interference in this legal case. Attorney General William Barr already created a firestorm by overriding the sentencing guidelines of the original prosecutors in the case, who resigned in protest.
Trump’s use of his pardon power can be distinguished from the other scandals of his presidency in that it is a perfectly legal, indeed constitutional, form of corruption. The fact a president can pardon his own criminal associates doesn’t make the action any better than actually impeachable offenses like obstructing justice or using foreign aid to advance his political fortune.
Rather, the very constitutionality of Trump’s actions makes them worse, because they show how the legal powers of the presidency are themselves ripe for abuse. Trump, by being bolder than his predecessors, has shown how easily a president can undermine the rule of law without even breaking any laws.
Rule of Law, ha.
If Trump Pardons Roger Stone, Blame the Constitution
It gives the president sweeping pardon powers that he’s more than happy to use for partisan and personal ends.