Each man (or, theoretically, at least) woman who becomes President bring with him/her a lifetime of experience, a worldview, a set of knowledge and wisdom, and a set of values.  The Office of President doesn't "erase" the persona of the occupant, it reflects it.

You reference to "Trump the man rather than Trump the President" is wholly illogical. The very problem with "Trump the President" is he is, in fact, "Trump the Man."  As I have often suggested, IMO, Trump the Man, as reflected in every facet of his life, meets the qualifications of a sociopath.  He is now President and, guess what, his actions continue to be consistent with those of Trump the (sociopathic) Man.  It would be foolish to expect anything else. 

 It is a cliche', (most cliche's have a large element of turth. that's why they're cliche's) but the best predictor of FUTURE behavior is PAST behavior.  Look at Trump's long and infamous personal, business and now political life. (cont)