Poor Stupidity! But why lay so much blame at her clumsy feet?! Especially when there is so much statistical evidence, which Discourse tells me is already linked in this very thread, showing that the guilty parties are Bigotry and White Supremacy.
You say that some of them [working class voters, presumably] voted against their own interests. I say when a person claims that a voter has voted against their own interests, that person has demonstrated a failure to grasp what the voter's own interests are.
It hurt them - deeply and daily - knowing a black family was in the White House. Knowing that our president was black. And for eight long years, they were angry and butthurt over it, every day. And for eight years, they did not hesitate to let the rest of us know about their butthurt.
Just as every day since the Election, they do not hesitate to crow about Trump. As one of them said to me, "Now you know how I felt for the last eight years."
And when I bite my tongue, take a breath, and very calmly and with as much empathy as I can muster, said, "You know, he's trying to hurt you, too. Not just me and mine, he's trying to take health care from you, too." How do you think they respond? Do you actually imagine they express something that you believe ought to be in their interests?
Good Lord in Heaven, no! They instead say something that to you may seem stupid, but which is actually in their interests. Often something like, "Yeah, but at least it's not Hillary."
To them, the abstract chance of dying of a treatable-yet-untreated ailment is not as bad as the horrifying certainty of living with the daily humiliation of a woman as United States President.
Instead of judging them to be stupid, you perhaps might try to listen to what they are telling you is how they see the world. And perhaps, you might avoid, or at least be more prepared, for your next devastating Brexit.