Check your history.  Nixon and Clinton faced impeachment for obstruction of justice....lying to investigators.  That's why there's the common wisdom that the cover-up is more damaging than the original event.  Nixon didn't even authorize the Watergate break-in; he was impeached for his efforts to obstruct justice in covering it up.

This probably explains why Trump is so desperate to divert attention away from Russia's interference with the election.  He's vulnerable to charges of obstruction of justice for a cover-up.  Trump didn't plot the interference, but he did attempt to take advantage of it and is trying to cover up that he did so.