At least one .org website that I know of has been shut down because the USA pressured the US organisation that controls the .org domain into doing so.
They could repeat this at will for quite a number of sites.
An immediate step to prevent this possibility, if you run a website, is to register a domain that is controled outside the US.
I have not found one article that just lists them all, and who controls them, but most TLDs have their own wikipedia article, e.g. .org (US controled), .eu (not US controled, yay) etc.
Ultimately ICANN controls all of this, and that's a US orga too, and Trump could bully them into doing shit, too. But the people who know about these things don't seem to think that's a likely threat right now. Also ICANN seems to defer a lot of tasks to exactly these TLD orgas. After all the internet still is (somewhat) decentralized.
when push comes to shove, be prepared to use alternative namespaces such as the one operated by opennic ^[https://en.wikipedia.org/wiki/OpenNIC#OpenNIC_namespaces]
I already do but autistici.org isn't reachable through OpenNIC either. The explanation is, essentially, that they cannot edit existing entries from the lists they get from upstream (something about DNSSEC) and that they cannot legally hand out .org domains themselves.
But yeah, I think autistici/inventati will evtl. use a TLD that isn't under US control.
In any case, we, i.e. the non-US parts of the world, will have to tackle these things evtl. because even if things get better in the USA, I don't think they're going to roll back to before the Patriot Act.