People seem irrationally impressed with “but the president has a right to” arguments around obstruction. Obstruction routinely consists of acts you otherwise have a right to do. It’s not, like, some kind of metacrime that supervenes only on other crimes.
I have every right to burn my own correspondence! I have every right to give expensive gifts to my friends! If I do those things for the purpose of obstructing justice, the fact that I’d otherwise be entitled to do them is irrelevant.
There ARE thorny questions about the applicability of criminal statutes when they run up against constitutional prerogatives, but I don’t think they work as some kind of drop-dead obstacle at the investigative stage where you’re looking for patterns of conduct.
Which is to say, there are doubtless cases where, as Nixon said, “when the president does it, it’s not illegal” because Congress can’t restrict a constitutional power by statute. But that doesn’t mean you know whether this is one of those cases in advance of the investigation.
