I do know how words work…and how they do not.
Words are not magic spells or incantations by which we can corrupt men's souls. Words are not some dark and mysterious wizardry to be feared.
Words are but one small expression of ideas. Words are a means by which we share our thoughts. Words are neither more nor less than this.
We rightly prize freedom for words because we rightly prize ideas and thoughts. We prize that facility of Man which, in addition to the evil expressed in Mein Kampf or Putin's 2021 ethnonationalist screed denying the right of the Ukrainian people to their own sovereignty, has also gifted us with the Declaration of Arbroath, the Declaration of Independence, the Universal Declaration of Human Rights, and Dr. Martin Luther King, Jr's “Letter From A Birmingham Jail. “
We do not need to fear fascist ideas of ethnonationalism, for we already have their rebuttal. We have that in Galatians 3:28, in Thoreau's “Civil Disobedience”, in the words and work of William Wilberforce, and in countless other expressions and defenses of our universal humanity.
Your error lies in the false depiction of Mein Kampf as an “expression of free speech”. Hitler’s screed, much like Putin's a century later, is simply speech, neither more nor less. Neither Hitler nor Putin invented antisemitism or ethnonationalism, but merely exploited that hatred which already existed within their audiences.
This is why censorship is always the tool of the authoritarian, and never used by the libertarian. In order to ensure their hatred remains undiluted, the authoritarian must work to prevent alternative thoughts from being shared. The libertarian has no such burden. The sharing of thoughts authoritarianism fears animates and informs libertarianism.
Thus the core question in a debate over censorship vs free speech is ever and always this: Will we be authoritarians or libertarians? Will we seek freedom for all, or power for a few, and oppression for the rest?
Myself, I am a libertarian. My desire is simply to live and die a free man.