A scapegoat is someone or something that bears the blame for problems, misfortunes or the actions of others. Often, scapegoats are forced to take this blame unwillingly and are the targets of irrational hostility as a result. 
When searching for some means to publicize one's willingness to screw up a nation, it can be hard work to get people to listen to your (no doubt excellent) ideas and proposals. Why not cut out all that tedious formulating of policies that people might like, and simply find some unpopular minority to take the blame for society's ills?
If you can't think of a suitable scapegoat, just go with a popular choice: Jews, Muslims, Catholics, Protestants, heretics, atheists, communists, feminists, misogynists, homosexuals, liberals, conservatives, the ruling class, the working class, the unemployed, welfare recipients, minority races, miscegenation, White nationalists, immigrants, illegal aliens, space aliens, witches, vampires, the Devil, heavy metal, violent movies, violent video games, pornography, etc. etc. etc.
Like so much that is good and true it derives from Leviticus:
“”Leviticus 16:8 And Aaron shall cast lots upon the two goats; one lot for the LORD, and the other lot for the scapegoat.
Leviticus 16:10 But the goat, on which the lot fell to be the scapegoat, shall be presented alive before the LORD, to make an atonement with him, [and] to let him go for a scapegoat into the wilderness.
Leviticus 16:26 And he that let go the goat for the scapegoat shall wash his clothes, and bathe his flesh in water, and afterward come into the camp.