Quite a few states that went to Trump were heavily unionized and they liked what he was saying to them and felt like he was talking to them. Left right or centrist; it is the candidate that people feel is addressing them that they will vote for in the end.
There is the constant cry of “socialism” from people that do not know what it means. Bernie calls himself a socialist but he is more a Democrat With policies influenced by socialist theory. I cannot predict how that will play out.