From Wikipedia:

1. High self-esteem and a clear sense of uniqueness and superiority, with fantasies of success and power, and lofty ambitions
2. Social potency, marked by exhibitionistic, authoritative, charismatic and self-promoting interpersonal behaviours
3. Exploitative, self-serving relational dynamics; short-term relationship transactions defined by manipulation and privileging of personal gain over other benefits of socialisation

I think we can put big checkmarks on all three of those for Trump. We don't need a professional psychologist for that.

Which may be partially beside the point and argument the article is trying to make, but I still want to point these out.