Strongmen: Mussolini to the present by Ruth Ben-Ghiat is a must-read. Drop everything & find it.
In equal parts it's shocking & reassuring to know that tRump is following a typical demagogue's playbook as established by Mussolini & refined (so to speak) / developed by Hitler, Berlusconi, Putin, Bolsonaro, Franco, Gaddafi, Pinochet & others, including Mobutu Sese Seko Kuku Ngbendu Wa Za Banga ("the all-powerful warrior who, because of his endurance and inflexible will to win, goes from conquest to conquest, leaving fire in his wake"). Ben-Ghiat explains exactly what that playbook comprises, such as propaganda, corruption & violence, & why it works as well as how.
I see the effect of some of those tactics on many others than true believers, for example with the widespread contempt for the press, which has been so thoroughly vilified from the right that people of every political stripe shy away from supporting newspapers & reporters, making it harder for them to do their jobs. I know I'm compressing & I hope what I'm saying nonetheless reverberates.