Groupthink is a vital aspect of imposing Statist control. Identity politics is another way of phrasing this phenomenon. Here is the Wikipedia definition:
Groupthink is a psychological phenomenon that occurs within a group of people in which the desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome.
There are examples all through history of Statists using this as a tool to impose their authority over an unsuspecting proletariat. Hitler used this to convince his “group” they were being victimized by the Jews. If you did not agree you could be in serious danger, even though they were your harmless neighbors. This was already an ancient method then and is now being used effectively in the U.S. because it is beneficial to The Powers That Be, who are using it as a distraction. Groupthink is being effectively promoted within our State-controlled media to create division and resentment between various groups. Men against women. Gays against straights. Blacks against whites. Poor against rich, etc.
The more division and resentment, the easier a population is to control by turning them against each other rather than encouraging honest debate and respect for another point of view.
As proof of the effectiveness of this age-old method of imposing control, the entire Old Testament is devoted to warnings of how The Powers That Be endlessly divided the people into tribes, kingdoms, clans, and so forth. Then they would be turned against each other to claim and then maintain control of the populace. Groupthink enabled The Powers That Be to claim the moral authority to demand loyalty. Those not willing to participate in the favored groupthink to demonstrate their loyalty would be purged, often violently.