"A subpoena was issued to Richard Nixon to turn over his tapes. He made the argument that you can't subpoena a sitting president... He lost... in the U.S. Supreme Court in the famous... Nixon tapes case. In ', Bill Clinton made the argument that you can't make me testify, and it looked like that was going to go nowhere, so he finally relented and testified "voluntarily." ...[T]he argument that is made in... a memo [to Robert Mueller]... It's basically written to a kind of gullible, nonlegal public. It doesn't make any genuine legal arguments. In fact, there's a rather frightening statement... that it doesn't matter how corrupt the president's motives are. He can do anything with the Department of Justice, as though it's his own private law firm. It says, "I can even use the pardon power." Well, of course he can use the pardon power as a way of showing mercy to people, but he's begun using it as what I have called a giant and loud elephant whistle, basically telling people, "If you have my back and don't cooperate with the investigations into what Russia did, and what I did, and what I knew and when I knew it, I'll have your back." ...[I]t almost sounds like he's saying that he can pardon himself, and thereby evade impeachment. Well, first of all, the impeachment clause itself says that the pardon power does not extend to cases of impeachment. But if all he means is that he can pardon himself so that when he is out of office he can't be convicted, I think he's confusing himself with vice president Pence. Pence can pardon him if he leaves office, the way Ford pardoned Nixon, but as I show in an article with and others, the self-pardon is ruled out by the structure of the Constitution. The President can say, "Pardon me" if he steps on your toes, but he can't say "Pardon me" as an exercise of official power. That would be the height of regal arrogance, and we don't have a king, we don't have an emperor. In fact, one of our complaints in the Declaration of Independence against King was that he was using his royal prerogative to obstruct justice. Well, if this president thinks that obstructing justice in order to corruptly avoid discovering the truth is within his absolute authority, I think he's got a lesson to learn, and I think the American people will teach it."