"Trump voters are victims of their own choices."

That statement can apply to a lot of people, regardless of skin pigmentation or voting preference. 

"For example, they vote against unions, the main source of workers rights."

I wouldn't know why,  never belonged to a union myself, but it is probably because the unions aren't getting it done for the rank and file.

"Why do white working-class people vote against their interests? They don’t. Corporate Democrats have never advanced their interests—and at least Republicans offer a basic, if misleading, story about why they are getting screwed." 

https://www.thenation.com/article/why-do-white-working-class-people-vote-against-their-interests-they-dont/

A number of Trump votors took a calculated risk he'd follow through on his promises to improve their lot.

I'll leave it at this, the working classes, regardless of skin color, have a lot more in common than they do with the upper classes regardless of skin color or party affiliation.