1980s GI Joe is the most glaring example I can instantly think of.

I am still baffled by the fact that decades later some blue curtain bazinga in my guild in one of the games I played insisted that the good old days of cartoons had zero political messaging, unlike today, and his example was... GI Joe.

After I gave exhaustive examples of the political messaging of that show (everything from the plain as day glorification of the US military, the OPEC oil crisis being simplified as being backed and perpetuated by a bunch of terror-loving puppet governments... puppets of Cobra of course) and what I got back was, verbatim, "did anyone ever tell you... the curtains are fucking blue?"