Citing a fake General Michael Flynn tweet (She possibly didn't know it was fake), House Minority Leader Nancy Pelosi undertook to define the term scapegoat. "Scapegoat. Do you know what a scapegoat is? That means, in a community where people want to absolve themselves of guilt, they get a goat, and they heap all of the ills onto the goat, and then they run the goat out of town."
Not exactly, Nancy, but I'm glad you got the gist of it. In a society with Christian roots it is a biblical reference. The scapegoat under the law of Moses was a goat let loose in the wilderness on the Day of Atonement (Yom Kippur). The high priest symbolically laid the sins of the people on its head and then sent it (thus the sins, symbolically) away. But there was another goat necessary to complete the typology, which must die to pay the sins of the people.
Lev. 16:7-10 And he shall take the two goats, and present them before the Lord at the door of the tabernacle of the congregation.And Aaron shall cast lots upon the two goats; one lot for the Lord, and the other lot for the scapegoat. And Aaron shall bring the goat upon which the Lord's lot fell, and offer him for a sin offering. 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.