You've hit the nail on the head, Jeff.
(b) Whoever knowingly ... corruptly persuades another person, or attempts to do so, or engages in misleading conduct toward another person, with intent to
(1) influence, delay, or prevent the testimony of any person in an official proceeding;
(2) cause or induce any person to
(A) withhold testimony, or withhold a record, document, or other object, from an official proceeding...
It doesn't matter if you sit in the White House, it is still a crime. The corruption is all that Mueller needs to establish with evidence, and I think he is well on his way to doing that.