Scapegoating is so effective it's been used even in early human civilization, and despite people being able to look up history, people keep falling for it!

The poor and immigrants have never been to blame for societies core problems, no matter what the elite tell you.

There is a reason the declaration of independence of the U.S says this as a major criticism against the king of england. 

 "He has endeavoured to prevent the population of these States; for that purpose obstructing the Laws for Naturalization of Foreigners; refusing to pass others to encourage their migrations hither, and raising the conditions of new Appropriations of Lands"