Scapegoats was a necessary part of any political process that seeks to disenfranchise some segment of society. Here is how it works. First you manipulate the political process, usually in more or less secret ways, to bring about disenfranchisement. Those who are so disenfranchised eventually realize that and get angry about it and want do do something about it. Scapegoating becomes central, not to defuse the anger but to point it in a direction away from those actually responsible.
Here is a current example. For the past thirty years, the middle class in the United States has suffered economic stagnation with almost no growth if any in real income. This is despite more people in the family working and everyone working more hours. The middle class turned to consumer credit and then to home equity, expanded beyond all reason by a speculative bauble. Eventually the bubble burst; the credit markets dried up; consumption and thus economic growth declined; and unemployment skyrocketed.
The anger and frustration of the middle class as a result of these developments seek a target. Who or what is responsible? Who or what can be blamed, punished or reformed? It would not be productive if this anger and frustration would actually end up focused on those who have actually gained income and wealth during these same thirty years. The top five percent of American households have done very well during this period; the top one percent, even better; the top .5 percent, best of all.
Rather than have the middle class come to that little conclusion, it serves someone's purposes a lot better if that anger and frustration can be pointed at other targets. What could be better targets than illegal immigrants and poor people. Under the rallying cry of illegal immigrants taking jobs from American--nothing could be further from the truth in reality--immigration reform has been stopped dead in its tracks.
But the significant outcome is not that but rather that all that justifiable anger and frustration is diverted away from those who actually have a lot more to do with the root causes of the current economic stress of the American middle class.