As an incompetent narcissist incapable of accepting failure, Trump is driven to blame others for his setbacks. The fact that he is destitute of studying and planning skills and has little focus outside of those things that will bring his starved ego immediate gratification, he keeps will hidden from his consciousness.
It all adds up to a basically destructive personality that thrives on revenge. When he goes down, his kneejerk reaction is to bring as many others down with him as possible. (Republicans are quaking in their boots for good reason.) As has been said many times, the nasty names Trump applies to anyone who gets in his way is nothing more than a description of his own lack of character projected upon others.
Now I hate to bring up the Hitler thing, but had the Fureur been born with a silver spoon in his mouth, he and Trump would have been identical in every way. As it is their basic characters are one and the same. Both longed to inflict revenge on a world that they see as conspiring against them. Hate seethed within them. They functioned without pity or remorse — no sense of fair play except to believe that they are somehow being treated unfairly.
Sadly these megalomaniac types rise periodically as bacons of hope for millions of folks whose own shortcoming are desperately in search of others to blame. In this present American case many see the Donald as their avenging angel come to smite enemies real and imagined.
That large numbers of Americans feel a need to rally around Trump does not bode well for the future of our nation. Indeed, a plate fully of hate and revenge does not promise success either on a personal or national level.