> Neither one of them had any common carrier protections to protect or to lose by these policies.
That is precisely the reason sites had a light moderation touch for years. I'm not sure where you're getting that from? The consensus (from lawyers I was advised by personally) was that too much moderation would open you up to liability, and so most social sites just enforced their ToS without wading into full scale moderation.
> I can't name any prominent American politicians who really want social media to publish everything that's allowed under the First Amendment. Do you know of any?
I'm sure there's probably at least one, but I have no interest in what politicians say they want. They're so often the people the Supreme Court is protecting us from. To me the question is what principles should guide us, and my answer is the First Amendment.
> I don't think that he understands how broad the First Amendment actually is...
I think he does understand how broad the First Amendment is. I also think he's probably much more willing to sacrifice short-term (or even long-term) revenue than most people would expect. I don't claim to know for sure though. And he might change his mind in the future.