Violence is often acceptable. Sometimes it is even admirable. It is entirely ethical to conclude that if someone attacks you, you can use violence to repel his assault. Likewise, if someone or a group of someones were violently assaulting a third party, it would be not only unobjectionable, but heroic, to step in and stop the assault, even if the only way to do so was through the use violence.
This is precisely why the attack on Ngo was inevitable and why, in all likelihood, further attacks, from Antifa activists and others, will follow.
Pundits on the right have long rallied against the left’s misuse of words like “unsafe” or “violent.” We have long cautioned that, beyond doing a gross injustice to the English language, these misuses would ultimately beget something worse than an abuse of syntax.
Ngo’s assault — and the reaction to it — is that something worse. Once you buy into the idea that speech can be violent, the logic defending violence as a means of suppressing speech is almost unassailable.