That's it exactly. Donald Trump is a private, non-governmental individual. He is entitled to his own First Amendment right, his own opinions, and is entitled to say anything he wants to. But when someone like Joe Biden, the highest office-holder in the United States, uses the bully-pulpit to vilify half the voters in the country as "garbage", then what he's done has crossed the line into fascism.
If Americans turn a blind eye to something like this, who will be the next group of people he attempts to dehumanize in his Hitler-like manner? Jews? Christians? Rural Americans? Gun owners?
What he said was intolerable. And I have little doubt that Kamala Harris would not also abuse her power, the office of the presidency, and the US Constitution. Her record as Vice President speaks volumes about what kind of President she would be, judging by the fact that she is unable to separate her own policies from those of Joe Biden's.