I am not an American. I actually live in a country that was a kicking baloon of totalitarian powers for decades.

The first instinct of an autocrat is to strangle free speech of his critics. This has been the case since forever.

For all their errors, societies that do have wide freedom of speech rarely lapse into tyrannies on their own account. The freedom to say that the emperor's new clothes are bullsh*t is precious.

As for your historical examples, Weimar democracy was deeply flawed in that it tolerated party militias and a lot of violence in the streets. Once people are threatened physically, they will seek 'protection' from gangsters. But violence is something very different from actual words.

And China isn't a case of a democracy that was taken over by cunning speeches of its enemies. CCP got into power by winning a civil war.