The Constitution prohibits Trump from pardoning Roger Stone: law professor – Raw Story

...Specifically, the Constitution states that the president has “power to grant reprieves and pardons for offences against the United States, except in cases of impeachment.” The Constitution’s framers added this caveat, writes Brettschneider, because they did not want a president to have the power to pardon people who helped him commit or get away with high crimes and misdemeanors. ...
https://www.rawstory.com/2020/02/the-constitution-prohibits-trump-from-pardoning-roger-stone-law-professor/