"Shown beyond a shadow of a doubt" is for a jury to decide. The problem is we have an FBI and DOJ who are unwilling to investigate and prosecute the criminals we have in government. Sessions has not been willing to pursue criminal swamp critters like: Lerner, Lynch, the Clintons, Holder, Koskinen, McCabe, Obama, Jarrett, Comey, Clapper - just to name a few. All these people have lied to Congress (a felony) and many of them have performed overt criminal activity. These people have lied to Congress WITH IMPUNITY!
Trump knows he made a mistake in selecting Sessions. The lack of prosecution of the political class and the emergence of Mueller are at Sessions' feet. As I said in my post, the President is in a catch-22 situation with Sessions. If he replaced Sessions with someone who will fire Mueller and vigorously prosecute swamp-critters, could he survive the onslaught that would follow? If he doesn't replace Sessions with a prosecutor (an AG) who is not a respecter of persons, there will be no meaningful swamp draining and we may witness a coup brought on by the deep-state and its media allies.