Nor does the First Amendment protect speech which is slanderous, libelous, seditious, incites violence, or endangers others (e.g., "shouting 'Fire' in a crowded theatre" if there is in fact no fire). Moreover the right to regulate speech, such as that in question here, has historically been exercised by the states.
And, I would remind you, the First Amendment also guarantees the free expression of religion in the public square. So, if we are to apply absolutism with regard to speech, why not to religious expression as well? In that case, we have a conflict of "rights": Leary's speech "chills" Catholic religious expression. Which is more fundamental to our system of government? Try as I might, I can find no right to boorish behavior in the Constitution. Nor is that venerable document a cultural-suicide pact. Perhaps, then, you might consider that absolutism is the wrong standard.
Finally, I have cited numerous examples of this behavior directed at Catholics in particular. Taken together, and supplemented by so many other such incidents, they constitute a pattern of persecution. I will not apologize for taking what steps I can to secure the Constitutional right of Catholics to religious expression. Nor will I be content to live in a culture which has become a cesspool of vulgarity and pornography.
" Nor does the First Amendment protect speech which is slanderous, libelous, seditious, incites violence, or endangers others ...
Leary's words were neither slanderous nor libelous, principally because they were not directed at any discrete individual and no individual could claim measurable reputational harm flowing from the words.
His words certainly aren't seditious (we aren't a theocracy, yet).
And by your own argument (in which you endorse the chilling of speech by threats of violence against the speaker), the only violence or endagerment Leary's speech seems to incite is Leary's own physical harm at the hands of a theocratic zealot.
Moreover the right to regulate speech, such as that in question here, has historically been exercised by the states.
You wouldn't happen to have some examples of these remarkable state "speech" laws, would you?
Leary's speech "chills" Catholic religious expression.
Really? How?