I think the biggest danger for censorship in the US is public/private censorship cooperation. The government is prohibited by the First Amendment from censorin

I think the biggest danger for censorship in the US is public/private censorship cooperation. The government is prohibited by the First Amendment from censoring. However, due to the centralization of the Internet, most communication passes through just a few gatekeepers. Congress holds hearing decrying content that they do not have the right to officially censor, but nevertheless use this to make their wishes crystal clear. Present for those hearings are the leadership of these gatekeepers, who are also made aware of all the other levers that Congress has that could make their lives miserable - anti-trust, section 230, copyright, not to mention government contracts. Of course like Henry II who never actually ordered Becket's death, Congress doesn't actually order censorship, just makes it clear that censoring those things would make them very happy.