That's not how prosecutors or prosecutions work. You don't leave it to someone else to decide. If there were a case, it would have been brought. What you had here was Wiseman trying to coax the House into impeachment---nothing more. No next AG will bring any case as there isn't one.
Mueller was the investigator who gave the case to the prosecutor(Barr).Trump was not found not guilty.A future AG can decide differently than Barr and some 2020 democrat candidates have said their DOJ will do just that.