I think it's more specific than that. That area is called the "rust belt" for a reason. Steel workers there, and people who work with steel like car assembly line workers, think Trump will bring back manufacturing to the area, and thus bring back their cushy union jobs.
These people are stupid; anything they can do robots can do better. (Including, evidently, voting.

) Manufacturing may come back, but cushy union jobs won't.
I heard in another thread that coal miners may also have been part of this demographic. I would compare coal miners to tobacco farmers: They both produce a product that kills people, largely through air pollution, and they should both find other jobs.