The US government is not really involved in the social media censorship question.
But if it were widely involved, it would make the problem far worse, by applying more ridiculous censorship, in more ham-handed ways.
We know this already. Social media just gets rid of everything with "Nazi" in it; an otherwise reasonable UK government goes a huge step further, and
fines a pug owner 800 pounds for making a joke about Nazis.
Sends police around to question the nature of tweets. Sometimes arrests joking tweeters and charges them.