I'm very new around here, and I tried to read most of the posts, but the thread is kind of long. Maybe someone answered this question when it was posed, but I didn't see it.
You need three things for an obstruction of justice charge: 1) an obstructive act 2) a nexus between the act and an official proceeding and 3) corrupt intent.
The charge is obstruction of justice, if there is not any justice to obstruct, then how can there be obstruction of justice?
In other words, if there is no crime, then there is no proceeding to obstruct (real or potential). Without a proceeding there is no nexus between the act and an official proceeding. If the person knew in advance that they had not committed a crime, then corrupt intent (you know you didn't do it, becomes an attempt to end the titanic waste of time and resources. So, I don't get the attempts to file obstruction charges that the President will beat. You're wasting your time, and it only serves to make you look desperate and stupid in the end. You will be virtually guaranteeing him a second term.