Erich Fromm's name often comes up in reference to Trump being a malignant narcissist because he is the one who first formulated this as a psychological condition. Mental health experts beginning with Dr. John Gartner in his 2017 article in USA Today ("Trump's maligant narcissism is toxic") have been using this formulation of psychological conditions to describe Trump.
Erommw as a prolific writer probably best know for his books "The Art of Loving." and "Escape From Freedom."
One of his less known works, "On Disobedience," is particularly relevant today.
Various portions of "On Disobedience" were published in other works in the early 1960's. The book is espcially relevant today. You can read several of the first pages here.
This part addresses why people are so easily led by authority figures like Trump.
From the book:
Why is man so prone to obey and why is it so difficult for him to disobey? As long as I am obedient to the power of the State, the Church, or public opinion, I feel safe and protected. In fact it makes little difference what power it is that I am obedient to. It is always an institution, or men, who use force in one form or another and who fraudulently claim omniscience and omnipotence. My obedience makes me part of the power I worship, and hence I feel strong. I can make no error, since it decides for me; I cannot be alone, because it watches over me; I cannot commit a sin, because it does not let me do so, and even if I do sin, the punishment is only the way of returning to the almighty power.
In order to disobey, one must have the courage to be alone, to err and to sin. But courage is not enough. The capacity for courage depends on a person's state of development. Only if a person has emerged from mother's lap and father's commands, only if he has emerged as a fully developed individual and thus has acquired the capacity to think and feel for himself, only then can he have the courage to say "no" to power, to disobey.
A person can become free through acts of disobedience by learning to say no to power. But not only is the capacity for disobedience the condition for freedom; freedom is also the condition for disobedience. If I am afraid of freedom, I cannot dare to say "no," I cannot have the courage to be disobedient. Indeed, freedom and the capacity for disobedience are inseparable; hence any social, political, and religious system which proclaims freedom, yet stamps out disobedience, cannot speak the truth.
There is another reason why it is so difficult to dare to disobey, to say "no" to power. During most of human history obedience has been identified with virtue and disobedience with sin. The reason is simple: thus far throughout most of history a minority has ruled over the majority. This rule was made necessary by the fact that there was only enough of the good things of life for the few, and only the crumbs remained for the many. If the few wanted to enjoy the good things and, beyond that, to have the many serve them and work for them, one condition was necessary: the many had to learn obedience. To be sure, obedience can be established by sheer force. But this method has many disadvantages. It constitutes a constant threat that one day the many might have the means to overthrow the few by force; further more there are many kinds of work which cannot be done properly if nothing but fear is behind the obedience. Hence theobedience which is only rooted in the fear of force must be transformed into one rooted in man's heart. Man must want and even need to obey, instead of only fearing to disobey. If this is to be achieved, power must assume the qualities of the All Good, of the All Wise; it must become All Knowing.
If this happens, power can proclaim that disobedience is sin and obedience virtue; and once this has been proclaimed, the many can accept obedience because it is good and detest disobedience because it is bad, rather than to detest themselves for being cowards.