The statements below are by two prominent scholars of Nazism--articulating the nature of the relationship between a political leader and the constituents who embracing him.

Nothing more futile than claiming that a leader suffers from a particular psychiatric "disorder" or "psychopathology" (a sophisticated form of "name calling"). The leader may or may not be disordered in various ways. In any case, the nature of a leader's psychopathology tells us little about the sources of his appeal; why so many people follow him.

The statements below apply equally to Hitler--and Donald Trump.

Contained within these statements is a methodology for studying the relationship between leader and led. Precisely what a leader says that a populace finds appealing--this is an empirical question, requiring serious exploration and research.

Joachim Fest (1973): 

Were it not for the congruence between the personal and the social-pathological situation, Hitler (Donald Trump) could never have wielded such hypnotic power over his fellow-citizens. He could not have bewitched the masses if he had not shared their secret emotions and incorporated all their psychoses into his own psyche. When (TRUMP) spoke, the masses met, hailed and idolized themselves. An exchange of pathologies took place.

Ronald Aronson (1983):

What is most remarkable about (Nazism/Trumpism) is that it became enough of a mass outlook for a movement  to be organized around it. Weren't the Nazis (TRUMPISM) reshaping reality until it conformed to a distorted fantasy? Wasn't Hitler (TRUMP) giving voice to the malignancy, the irrationality of the social forces that brought him to power?