Why do immigrants get blamed for being paid so little? Why don't the companies that extort work at slave wages get blamed? Why do the weak always get blamed as the rich keep all the money? If your businesses paid a fair wage this wouldn't be a problem. But they don't So maybe you could be mad at them. It's like blaming a woman for sexual harrassment because she is beautiful and tempted her harrasser. How will closing the borders prevent these businesses from sending jobs out of the country? It seems the problem is not with the immigrants but with the souless businesses.
We have the same problems in America---but I'm not going to blame a poor class of people that are just trying to eat. I blame the companies that take advantage of their disadvantage. When things get scary, it's human nature to look for a group of people to blame even if they aren't the cause. Look for the cause and go after it. Germany suffered terrible economic crisis and it was easy to blame the Jews. It is flawed reasoning. But that is my opinion, of course.
NC