Yeah, if you asked Trump supporters to find Haiti on a map, I'm guessing a single-digit percentage is getting it right. Their prejudice towards immigrants is not some calculated, historically-informed position. It's a basal fear of the other.
I don't even know what they got independence from. France, hundreds of years ago? Why would I care? To equate white people with the French definitely seems racist to me.
That is the great thing about hate it doesn't really require specific knowledge. Most of the people who lynched black folks in the south didn't have a lot of specific understanding of the cultures or history of the people they hated they had a sort of diffuse hatred based on nothing real. Assuming that historical issues aren't a root of anything because the rabble doesn't specifically understand why they are supposed to hate someone is just a basic misunderstanding of how people work.
It's like thinking the smell of shit doesn't come from the turd because the people smelling it can't actually see it.