One additional thing. Dems and pubs did not enforce immigration laws. For dems, they produced dem voters. For pubs, they provided cheap labor for business, who is often who pubs really cares about. So the white and black blue/pink collar worker has his or her relative earnings decline because no one really wanted to enforce an inconvenient law. That is real, it does not justify Trump, but they have right to feel cheated and let down by both parties.