Reddit reviews The Inner World of the Psychopath: A definitive primer on the psychopathic personality

Avoidance of responsibility is a primary characteristic of psychopathy. He ticks off all the other checkmarks, too. Only libel laws are protecting his ass from being called a psychopath openly. Educate yourselves about psychopaths -- I recommend these books I have read to understand my own lifelong contact with psychopaths, starting with my mother:
Without Conscience: The Disturbing World of the Psychopaths Among Us
Snakes in Suits: When Psychopaths Go to Work
Confessions of a Sociopath: A Life Spent Hiding in Plain Sight
The Psychopath Test: A Journey Through the Madness Industry
The Inner World of the Psychopath: A definitive primer on the psychopathic personality

He is commonly called a narcissist, but here's a handy rule of thumb. Not all narcissists are psychopaths, but all psychopaths are narcissistic. It's easy to understand why -- they don't see humans as humans, only objects to be manipulated for fun and profit. They, themselves, are the only conscious being, so nothing else matters. Their brains aren't wired to understand we have minds and memories, which is why they lie constantly to achieve their immediate needs. Strangely, the inability to experience emotions (and that includes fear, which is why Trump seems to never give a fuck about consequences) comes with no sense of past or future. There is only the "now."

1% of the population are psychopaths. You know more than one. Some say it's an evolutionary adaptation that exploits humans with emotions and morals, and that they are "intraspecies predators." There are professions that rely on psychopathic behavior, and you can draw your own opinions on them:
The Wisdom of Psychopaths: What Saints, Spies, and Serial Killers Can Teach Us About Success

It is also commonly said that psychopaths are experts are reading people. This is false (because, to them, there is nothing to read). They are simply experts, from lifelong experience and practice, at putting people into situations with predictable reactions. For example, Trump likes to insult people because he knows it distracts them and takes them off their game as they try to defend themselves. Psychopaths like to do their manipulating in the background and behind peoples' backs (and in Trump's case, behind NDAs and hush money), thus Trump's biggest problem -- he's the world's most watched person and nothing goes unnoticed, so his previous tactics aren't working. He is thrashing more and more as he gets more desperate to deceive. He is not losing his mind or getting senile. He's a psychopath who can't understand why his old tricks are no longer working.

His apparent "humanness" is a practiced façade, as is true for all psychopaths. They learn, starting in childhood, how to fit in. Some learn how better than others. Trump is good enough at it to fool a large number of voters.
BTW, there's nothing saying a psychopath can't also be dumb as a brick or illiterate.