So, the other thing about McGahn is that Trump tweeted essentially calling him a liar. And now he wants to prevent McGahn from testifying.

But apparently, in all their legal mumbo-jumbo, the one thing they DIDN’T assert was that the WH could BLOCK McGahn from testifying. All they claimed was that Congress couldn’t compel him to testify.

This is the key point:

Although OLC’s opinion says the President can “direct” McGahn not to testify, it identifies absolutely zero legal basis through which the President could _stop_ McGahn from appearing voluntarily.

If such a basis existed, trust me, OLC would’ve cited it. https://t.co/YyjXvLkziz

— Steve Vladeck (@steve_vladeck) May 20, 2019