Three different times during Bill Barr’s confirmation to be Attorney General, he agreed that agreeing to pardon someone for false testimony — as Donald Trump just did for Mike Flynn — would be a crime.
Patrick Leahy, specifically invoking Barr’s sanction of the Caspar Weinberger pardon that squelched the Iran-Contra investigation, asked Barr about pardons.
Leahy: Do you believe a president could lawfully issue a pardon in exchange for the recipient’s promise to not incriminate him?
Barr: No, that would be a crime.