Indoctrination is saying something enough times that people internalize it as one of their core beliefs that control how they act. Indoctrination is especially effective on children, and even more so if the information is from an authoritative source. Indoctrination is the most influential method of conditioning a society to a particular message; the message itself is called propaganda; not necessarily a negative thing unless you want a competing message, which is why highly propagandized societies tend towards censorship. Those who control the propaganda control the indoctrination, which means they control society.

Propaganda comes from Catholicism and means to propagate their faith. Politics is a secular religion, and uses propaganda is the same way. The political Left knows the value of propaganda, and it fits well in their collectivist, egalitarian view of life. The Right, focusing on individual autonomy, tends to overlook the value of propaganda, even though they were more molded by it than anyone, which puts them at a distinct disadvantage in the control game. The Right doesn't seem to understand that Media, Entertainment & Education are the primary sources of propaganda, and have ceded them to The Left, to their own future demise.