I have always held out the belief ( perhaps veiled hope) that Trump will not complete the term. Of course his exit will be voluntary and populated with comments about the fake news, msm, leakers, and losers as his reasoning for departure. I truly think the entire campaign was an ego satiating exercise and padding for his self held belief of his greatness and his ability to win at all he does. We all know he has claimed supremacy when he has lost battles, legal and otherwise - and becoming POTUS is just another feather in his visor - after all he has played more rounds of golf since winning than his critical analysis of his predecessors times on the links annually. 
He will quit, under a cloud of quasi criminal accusations and truths but will do so upon the winners podium he has self erected.