It started in earnest with the Southern Strategy, ramped up with the evangelicals in the eighties, fermented with AM radio hosts like Limbaugh, and finally birthed itself in the form of a pussy grabbing con man who benefited from decades of name branding.
It's always been there. I think back to a particular adult of my childhood and two direct quotes:
"I don't hate black people. I just hate ni@@ers."
Upon seeing Kim Bassinger on TV while sitting next to his wife - "I'd give my left nut just to smell her pee."
Trump let all these people say shit like this in public. That's the substance of his cult of personality.