This is another "we have to kill free speech to save it" spiel. I don't find these arguments convincing and the use of Hannah Arendt is particularly egregious. Hannah Arendt was not (and never claimed to be) a philosopher. She was a political theorist who tried, in her own words, to "look at politics with eyes unclouded by philosophy".

> Looking back at the rise of fascism and the Holocaust in her 1951 book “The Origins of Totalitarianism,” the political philosopher Hannah Arendt focused on the use of propaganda to “make people believe the most fantastic statements one day, and trust that if the next day they were given irrefutable proof of their falsehood, they would take refuge in cynicism.”

The author uses this quote to stand for "in other words, good ideas do not necessarily triumph in the marketplace of ideas". But that's not at all what Arendt was saying. She believed that, in the end, the truth will come out:

> Under normal circumstances the liar is defeated by reality, for which there is no substitute; no matter how large the tissue of falsehood that an experienced liar has to offer, it will never be large enough, even if he enlists the help of computers, to cover the immensity of factuality. The liar, who may get away with any number of single falsehoods, will find it impossible to get away with lying on principle. This is one of the lessons that could be learned from the totalitarian experiments and the totalitarian rulers' frightening confidence in the power of lying--in their ability, for instance, to rewrite history again and again to adapt the past to the "political line" of the present moment or to eliminate data that did not fit their ideology. Thus, in a socialist economy, they would deny that unemployment existed, the unemployed person simply becoming a non-person

> The result of such experiments when undertaken by those in possession of the means of violence are terrible enough, but lasting deception is not among them.

The power required to eradicate the truth, she writes, "would amount to omnipotence". Hitler, Stalin, and other totalitarian leaders undermined their own governments in their attempt to destroy the truth and rule through terror. For Arendt, all political power flows from consensus. She believed, contrary to Mao's quip about "political power growing from the barrel of a gun," that violence and coercion cannot create political power but can only undermine it.

That sounds optimistic to me. By encouraging the citizenry to simultaneously believe everything and nothing, these regimes undermined themselves.

The article sees strong defense of free speech as naivete:

> It’s a fundamentally optimistic vision: Good ideas win. The better argument will prove persuasive.

I don't agree with this interpretation of modern liberalism. The modern liberal position on free speech is not optimistic, it's resigned. The argument is not "everything that rises must converge" but, rather, we are stupid, limited beings, so what right have we to interfere with other stupid, limited beings? This position amounts to a recognition of the limitations of human rationality, not a celebration of it.

It has been personally sad to me to witness the left turning on free speech. When I was a kid, it was the lefties who defended free speech. It was Chomsky who said "with regard to freedom of speech there are basically two positions: you defend it vigorously for views you hate, or you reject it and prefer Stalinist/fascist standards". Now that I'm a little older, I realize that, mostly, people just defend free speech when they stand to benefit from it (i.e. when they aren't in the position to censor).

These days the left has a lot of cultural power and many on the left are bowing to the temptation to use that power to censor the opposition.