First, they assess the value of individuals to their needs, and identify their psychological strengths and weaknesses. Second, they manipulate the individuals (now potential victims) by feeding them carefully crafted messages, while constantly using feedback from them to build and maintain control. Not only is this an effective approach to take with most people, it also allows psychopaths to talk their way around and out of any difficulty quickly and effectively if confronted or challenged. Third, they leave the drained and bewildered victims when they are bored or otherwise through with them.
Whether or not Trump qualifies as a psychopath or a malignant narcissist (they are closely related), he has a long public history of behavior patterns that fit this description, even though he has never worked in a normal corporate organization, the setting described in the book. Those qualifications, which would loom large for any therapist treating Trump, pale in comparison to the similarities that matter to us as citizens. Trump has traversed the trajectory described countless times, with customers, business associates, lawyers and wives. Why shouldn’t he do the same with everyone in the political world as well? And if he actually does deviate from the pattern for some reason — which is always a possibility — understanding his behavioral baseline will still be crucial in making sense of that departure from it.