As the original article points out, the first half of the 20th century was dark time. And I'd be surprised if the present day court would rule the same way if the literal facts of the Chaplinksy case were repeated.
It's an example of what I was talking about above: it's right that you aren't allowed to use your freedom of speech to incite violence. But the court in Chaplinsky extended that to protect the violent. It's a good thing that courts have been moving away from that heckler's veto.
But I fear the way the politics of outrage is going, in 40 years time we will back to authoritarian norms that brought us two world wars.
Still, speech isn't somehow inherently harmless or different from other actions that we take. It's bad to take someone's things with a knife, but I'd say that it's even worse to take someone's humanity with a word.
"You cannot, sir, take from me anything that will not more willingly part withal – except my life, except my life, except my life." -- William Shakespeare
But a demagogue sure can. I guess it would be more accurate to say that they take humanity from a lot of people who belong to certain classes with a lot of words, but that's a messier metaphor.