First of, using "they" and "simplistic view" in one sentence doesn't work, because it makes a generalized simplistic argument while using itself.
"disprove for yourself if you weren't just looking for a convenient narrative given"
How does "Millions of white Trumps voters are racist" contradict "that Trump had significant minority vote (30-38% of Hispanics [...]"? First it assumes Hispanics can't be racists - everyone can be a racist, racism isn't a "white" thing. Second those Hispanics also want a 50s America with wealth, a good job, traditional values and a future. That was the reason many of them or their parents came to the US (if they haven't been conquered during the expansion of the US to the west, e.g. in the Mexican-American war of conquest). And the most ardent fighters against immigration are those who immigrated last. Trump is a sexists but more women voted for Trump.
Of course things are not mono causal, but than what is? There is not one reason the Earth goes around the sun exactly in the way it does, nevertheless we talk about gravity as a thing. Or the apple falls down the way it does, nevertheless we talk about gravity.
The US enjoyed a boom for various reasons in the 50s and on average people in the US became (or perceived themselves) poorer since then - also for various reasons. People want the 50s back with neat houses, nice cars and a life time job from General Motors. Todays world is complicated and the reasons for why the US and other countries are in the state they are is complicated. And the 50s in the mind of many people was nice and simple.
But for Trump voters it boils down to the rise of black people and hispanics(as can be seen in spike of growth in resentment after Obama became president and millions felt they are ruled by a black person now, e.g. see spike in militia groups). Instead of understanding the reasons for the downfall in (perceived) wealth it boils down to a zero sum game where "what other people get, I don't have".
The fall of the American empire since 1990 has accelerated this believe and has lead to Trumps "make America great again".
I'm with Forrest Gump, “Stupid is as stupid does". Not about what people think or how they see themselves. Were 1933 Germans racist? Götz Aly has shown ("Der Volksstaat") that Germans profited a lot from Hitler materially, so were they racists or just opportunists?
Racists explain the world in races and declare themselves victims of another race (Jews, Blacks, Tutsi, ...). Racist people very seldom see themselves as racist. People become racists when they think they are unfairly treated compared to others and when they get into dire economic circumstances.