That's not how it works, at all. Russia didn't become a dictatorship after censoring fascists. Quite the contrary, in fact. By giving a platform to fascism, you risk losing all free speech once it gains power. That's what's happening in the US.

Censorship is not a way to dictatorship, dictatorship is a way to censorship. Free speech shouldn't be extended to the people who actively work against it, for obvious reasons.