Here is the "Psycopathy Checklist" which is a popular method to diagnose psycopaths. It reminds me of a certain someone.
-glib and superficial charm
-grandiose (exaggeratedly high) estimation of self
-need for stimulation
-pathological lying
-cunning and manipulativeness
-lack of remorse or guilt
-shallow affect (superficial emotional responsiveness)
-callousness and lack of empathy
-parasitic lifestyle
-poor behavioral controls
-sexual promiscuity
-early behavior problems
-lack of realistic long-term goals
-impulsivity
-irresponsibility
-failure to accept responsibility for own actions
-many short-term marital relationships
-juvenile delinquency
-revocation of conditional release
-criminal versatility

edit: We also shouldn't diagnose Trump with anything right away, because that's not our place. But I just think it's very interesting