Mary Trump sets out the family structure and history which created the monster we know as Donald J Trump.
The family is dominated by a patriarchal narcissist who picks a golden child and a scapegoat. Mary Trump's father Freddy becomes the scapegoat after 'not towing the line', not being 100% compliant to his fathers wishes and attempting to follow his own path. This was unacceptable to Fred sr. who then dismantled Freddy's self confidence by gaslighting him. Donald was made the golden child because he had the talents of lying, bragging and cruelty. Donald's elevation was also useful as a punishment to the far more deserving and capable Freddy.
Don was supported in everything that he did, not just funded but also bailed out when he failed. Fred helped to create the myth that Don was a genius businessman - partly to get some of the reflected glory, after all, any business success that Donald had would be because of his father's planning, power and influence. Don was not the one doing the deals - until he started building casinos, which ended very badly. When Don was in charge it generally went to shit.
Freddy on the other hand was criticised for his successes as well as his failures. Being a pilot was not taken seriously but rather dismissed as childish 'flying around'. Anything he did was criticised and compared with Donald's amazing successes, most of which were illusions, lies kept up by Fred injecting cash into Don's failed enterprises.
Fred, not surprisingly, becomes dis-heartened if not depressed while Don burns through millions (of somebody else's money) to keep up the charade of success. The more Donald is indulged and baled out, the more grandiose he becomes until he gets to the point where it doesn't seem ridiculous to run for the presidency. The monster is loose and cannot be controlled, even by those who made him.
This is a tragic and salutary tale, but it's a family situation which is far from unique. A narcissistic father creating a narcissistic child and a scapegoated child is a common family system creating misery across the western world. Trump is, I believe, making this worse by acting as a role-model for the narcissists in the wider world. They can see his tactics on TV nearly every day and see just how well they work. You don't need to be President to abuse power, at the very least the lowly narcissist has some power over their victims even if it's just the knowledge that most people will behave decently and not make a scene. That can be enough to flip things in their favour and get them onto the first rung of megalomania.
This family dynamic forces the scapegoated child to bury their talents and abilities so as not to outshine the narcissistic sibling. If they can also be made to believe that those talents are worthless or even embarrassing then so much the better. It really doesn't matter why they hide them so long as they don't interfere with the narrative that "Don is a genius deal maker". This can have very harmful effects on the life of the scapegoat, even to the point of suicide or life threatening addiction as with Freddy Trump. It is also very damaging to the golden child who loses themselves completely to a lie that they can never live up to.
The narcissistic patriarch has to switch the roles of the talented child and the loser child because the talented child is a threat to him. The able child might show him up, reveal that the narrative of his own success is also a sham.
In order to break out of this narrative, the scapegoated child needs to see the narrative for what it is - a load of hogwash! It's a lie, the family is a cult. It can be very difficult for the scapegoat to see this when the rest of the family is firmly entrenched in the lie. When everybody else in the family says that Don is a genius and Freddy is a waste of space, there must be some truth in that, right? "It can't just be me who thinks that I am not awful and that the real villain is Don?" Even once the able child has realised this they still risk being reeled back in by one of the many tactics that families use to erode boundaries.
