actually, they are only supposed to be investigating Russian collution nothing else. That's what the investigation is about Muller is liable to get his panties in a twist when they start investigating him because he has gone way beyond his original order. What Trump did BEFORE becoming president as long as it was not illegal is BS
Trump is giving Mueller enough rope to hang himself.
Mueller is facing treason charges by delivering Hillary's uranium sample to the Russians from Her illegal criminal sale to the Russians anyway.