Constitutional amendments are also an extremely high bar (2/3rds in congress + 2/3rds of state legislators), so much so that they never even try them anymore. So adding a hate speech amendment or "sending offensive messages" law, like the UK did via parliament, would basically be DOA in the US.
But of course all rights can hypothetically be taken away in any human system, if there's enough public support or obedience.
It's genuinely hard to see a way out of complete degradation to a failed democracy at this point. None of this is hypothetical either. Sometimes I wonder if people on this site read the news at all, or are just willfully ignoring the reality of the situation.
Do you think Black Americans, or native Americans feel shame when visiting these museums?
Or are they not "our people" to you?
The 'pen' says they are not allowed to keep grazing their cattle there in Clark county, yet they still are to this day.
This broke down instantly as soon as the same party got all three branches of government.
The actual place to look for serious US speech restrictions is "obscenity", like the Comstock laws, and modern things like Mississippi Internet age verification.