I freely concede that I'm doing a poor job of defending it, because it isn't my view to defend. The part of it that I don't understand is limited to how it is self-consistent, which is not something I see addressed in your reply, although I could be mistaken.
But I think we are still saying talking points instead of getting to the core. I understand and I share the concern about an important voice being silenced. But I think the mechanism of that silence in the current environment is probably related to loudness of noise rather than quietness of signal. Obviously, it may be different at different situations and times in history. But I think if our goal is to hear quiet voices we ought to consider both sources of the issue pretty seriously. A philosophy that only considers the problem of transmitting and ignores the problem of receiving through a noisefloor seems an incomplete troubleshooting procedure to me.
Whereas you perceive a threat about the slide into censorship, I perceive a threat about the slide into unrest and violence. In reality, it seems likely we will get both: one of them first and the other following as a reaction. So I think our interests would really be best served by hammering out a workable compromise so as to hang together rather than separately.
I agree that we ought to return to the "liberal discourse", but we may perceive its makeup differently. Limitations on discourse have always been part and parcel of the institution. Some limitations have been very harmful. Others, like 'you can't threaten not to leave when you lose an election', have been very helpful. Liberal discourse is presently threatened because we have abandoned that sort of polite limitation, and it is by reintroducing it that we can recover the institution.
> If we had an oracle of truth, then censorship of falsehood would be easy and practical. We also wouldn't need democracy at all, we could just ask the oracle of truth what to do, and do it. But we don't have any such creature.
This is a bit of a strawman. I do empathize with the skepticism of authority in our present climate. However, you rely on some method to determine whether a person is doing censorship in the same way I rely on a method to determine if a person is doing misinformation. I expect it is a similar method, which is to say, imperfectly, based on values present in our historical age, individual biases, and so on. Which is the "same sort of stuff" that democracy otherwise uses to make any of its decisions.
I expect this dispute arises because, in your worldview, limiting the discourse is very exceptional, and doing it properly should require an exceptional method. Whereas from my perspective, laws, elections, jail, and wars are very serious, and we have processes to decide those.