Isn't Trump kinda the one to bring that about tho? Idk much about howard dean, but I assume he was at least somewhat respected as a politician beforehand. With that scream, in a kind of patriarchical society creating a mythos of education and prestige around politicians, revolving around political etiquette that scream is simply seen as infantile and unserious. Trump entered politics as that kind of infantile and unserious candidate in the first place, being a cartoonish, stereotypical, Saul Goodman-esque figure. In the end, it's all about expectations that people set. Nobody believed agent orange would win, but in the end he did because he represented a kind of tonal shift in american politics, not to mention straight up saying what all these bourgeois politicians already believed anyway. In the same way LGBTQIA+ want to practice their sexuality without the fear of being killed, beaten or prosecuted, that is the same way in the opposite direction in which fascists want to freely express their racist, sexist, homophobic views without any consequences. Trump said these things out loud, and republicans found him 'cool' because he didn't beat around the bush, at least in the public, about their true beliefs.

Ultimately, Trump isn't some anomaly. He's just a natural unmasking of the fascist paradigm of amerikkka.