I think @ChaosEngine summed this up nicely:
I don’t believe that everyone who voted for trump is racist, but it is demonstrably true that they supported a racist.
And you can argue that Hillary had some unsavoury characteristics too, and I wouldn’t disagree with you. The difference is that most Democrats will admit to her faults (it’s probably why she lost).
Trump supporters, OTOH, either deny his racism, or worse, actively support it.
Also worth noting that you can be opposed to illegal immigration and yet still believe that people should be treated humanely.
This cannot be emphasized more. It's not about whether Trump voters or current active Trump supporters exhibit racial bias or prejudice in their daily life: it's about the fact that they voted for a man who is a racist. Many many people in the US can't get past this simple fact here. Somehow the voters/supporters either simply didn't care about this fact, or genuinely believed that Trump is not a racist. Then there's the whole notion of the fairly large amount of people (granted, maybe a minority of the whole US, but still an uncomfortable number of people) who still go to great lengths of mental gymnastics to deny or defend his racism.
I don't think you'd find many Hillary voters who would go to such great lengths to defend her flaws. Most of us that voted for Hillary knew she was a flawed candidate, for various reasons.
The point is that this is less about labeling and more about actions that we see and hear on a frequent basis, in many cases from people we may actually know personally.
Yea maybe people didn't vote for Trump because he's a racist. But people who voted for Trump did, at the minimum, ignore this, and that is very troublesome.
This primarily has to do with the sheer amount of influence and money that the two large parties have had.I'm not very sure what more there is beyond that that has caused this situation. Historically, the US has had more than 2 major parties. This trend is a trend from the last century.
But yes, more choices would mean we may have had a possibility for a more sane electoral competition, like Hillary vs Bernie.
However, Trump was not a result of only 2 parties being present. This exacerbated the result, but Trump was nominated by the Republican Party, let's not forget. There's more to this than that.