I think it is fair to say that Trump on the right and Sanders on the left have trouble with 1) immigration because it “takes jobs from Americans”, and 2) trade becuase it “takes jobs from Americans”.
In a piece that’s anti-Sanders, but could just as easily be anti-Trump, Daniel Bier hits the nail on the head:
This is where economic ignorance stops being morally neutral and becomes a real threat to the life and well-being of the poor, especially in the developing world.
Not content to merely keep Mexicans from working in the United States (where, thanks to US capital and infrastructure, they could earn three or four times more than they make in Mexico), Bernie Sanders now objects to the right of Mexicans to work in Mexico, if they dare to sell goods and services to Americans — or, God forbid, try to compete with American firms.
Read the whole thing, entitled “Bernie Sanders Anti-Foreign Crankery”. Lots of good data there too, that many seem blissfully ignorant of.