For example, antisemitism and homophobia are two concepts that the parent thinks should be banned. But that right away leads to contradictions. If I ask you a question, “Should orthodox rabbis marry gay couples?” your answer could be deemed as either antisemitic (“yes”), or homophobic(“no”). Your best bet is to stay silent on that question!
So, I do understand not wanting to allow directly threatening speech on a specific group. It’s just such a tricky thing to codify such a ban without inadvertently stifling freedom of thought and opinion. What you really do is hone the dog-whistling capabilities of those who would organize to commit violence.
Edit: But even with that said, I agree restrictions to speech should rather be too few than to many, and too narrow rather than too broad. Which is why I think the line should never remotely try to cover every degree of racism or xenophobia at all. I could be convinced of the need to restrict public calls for genocide, for example, though.
This isn't an exception to free speech protections.
'In 1942 the Supreme Court held that the government could prohibit "fighting words" — "those which by their very utterance inflict injury or tend to incite an immediate breach of the peace." The Supreme Court has been retreating from that pronouncement ever since. [...] the only remaining focus is on whether the speech will provoke immediate face-to-face violence. '
Quoted from https://www.popehat.com/2015/05/19/how-to-spot-and-critique-...
But, ok, if you want another U.S.-based exception: some information regarding nuclear weapons is considered to be 'born classified' in the sense that even if you develop it on your own without clearance or access to classified materials, you still are not allowed to divulge it. That is another government-enforced restriction to free speech, although admittedly a sensible one on the justification of the survival of the species.
Don't get me wrong, I think in any specific discussion about speech restrictions the bias should be huge in favor of free speech, given the obvious dangers of any too broad restriction and the incentives of people in power to put in place such restrictions. But we definitely don't currently enjoy, let's say "absolute information-theoretical freedom of speech" (e.g. including things like direct actionable threats, weapon blueprints, video-recordings of certain third-party crimes, etc). We already put up with some limits without falling into a slippery slope. 'No explicit calls for genocide' might not, on its own, be the restriction that opens the floodgates to pervasive censorship.
I mean, the U.S. already has one of those, the whole "fighting words" exception, other countries have a few of their own. It is not entirely clear to me that banning say "open calls to organized violence or coordinated reprisals against members of an ethnic or religious group, on the basis of membership into such group" would be to the detriment of political discourse.
Don't get me wrong, as I said, I am more often on the corner of extreme free speech than its opposite, but saying that the only other alternative is broad censorship is a bit of a strawman. Even with things like eugenics, which I do find instinctively abhorrent, you can easily craft a clear line where things like "I believe group A is better at X than group B, here is my social science study about it and supporting evidence" are perfectly valid speech (and people can engage with that if they so wish and counter speech with speech until the truth emerges), but where continuing with "therefore we must get rid of all B" is considered axiomatically unacceptable. One is a question of facts, the other is a matter of societal ethics.
As for Mexico, by the way, since I am from there, let me point out that the issue with the safety of journalists in the country now a days (vs say in the sixties) has very little to do with whether we have freedom of speech as a value (we do, both legally and as a society, maybe not to the extreme of the U.S. but to a higher degree than many countries where this is not as big of a problem). The issue is the weakness and capture of the state, where no matter what the people want or the laws say, the state is not able to protect people or enforce laws (in part because it is materially incapable, in part because it is corrupt and colluded).