Word of the Month: Index
Gleich is an adjective/adverb/prefix indicating that something is the same as or indistinguishable from something else. For example, if two people have "die gleiche Meinung", they have the same opinion. Schaltung refers to the sum of the connections between the components of an electrical, electronic, or mechanical device as depicted, for example, by the wiring diagram of an appliance. In a car, Schaltung refers to its gear mechanism.
Combining the two words we get Gleichschaltung. The term refers to the enforced uniformity of opinion and purpose in the administrative and cultural institutions of a country—the goal is to have them all "wired the same" in the end. The emphasis is on "enforced": Gleichschaltung doesn't happen by itself, but is always ordered and orchestrated from above, like when independent reporters at state-owned media are fired and replaced by conformists.
Gleichschaltung typically accompanies the beginnings of an autocratic regime or a dictatorship, starting with the media and moving on to the civil service, especially the judiciary; the police; the military; the arts; and eventually the universities, when professors critical of the regime are fired, if not put in jail, and research challenging the official propaganda is suppressed.
Getting the media under control is always an important first step because it takes away peoples' ability to receive uncensored news and to learn what's really happening in their country. We saw this taking place when Putin came to power in Russia and now in Turkey, where Gleichschaltung has already reached the universities.
Acknowledgment. I would like to thank Al Rodbell for pointing me to this term, which has lost none of its relevance [more about this in my comment].
Labov memorial event at the LSA
29 minutes ago