Republicans have always relied on racist rhetoric to win elections, so that part was a given. What was different that allowed for such a circus clown to even get a big enough platform for his demagoguery was the break down of trust in the media and in the political establishment. People outchea having to go on google to self diagnose and find ways to treat themselves at home while these politicians play games with our lives, they (we) are sick of it. It's the same reason why despite the bernie black out and clear media and DNC bias against him, he is in position to garner the same kind of reactions as these:
Even Yung Bern had to eat a whole ass crow. Can you imagine how he felt? Or how his supporters felt knowing that even republicans were trying to keep him from winning and failed? Any republican that understood what was going on could have appealed to the crowd of people who were 100% done with this sham of a political shell game and made good on it.
(which is the real scary part)
The only way you could have countered that was with another populist, a REAL one and they decided to trot the wicked witch of the white house out there because...entitlement, she's American royalty after all.