Here is more of a pure philosophical response (vs a political science, political or policy response) in a rough form of a syllogism.

(1) The Constitution protects free speech. (Free speech could be banned otherwise.)

(2) A number of people are diligently trying to effectively abrogate the Constitution (but deny this is their objective) and might succeed in their attempt.

(3) These people use speech (and other tools ) to achieve this.

(4) If they succeed, there will be no more free speech, because free speech would threaten their achieving and maintaining their desired end result.

(5) Speech (and other actions) that effectively undermine and destroy the Constitution are not protected under the Constitution, and should effectively destroyed, in order to maintain the right to free speech.

Imagine a football game in which one team decides to win without playing by the rules (including severely injuring players on the opposing team).

Such a strategy would enable them to win the game, regardless of the penalties the referees impose. The referees have no way of stopping this because all they can do is impose penalties.

I don't know exactly why, but there is something wrong with thinking "these are just two teams each playing the game and trying to win." If part of "playing the game" is playing by the rules, then the team in question is not playing the game. (I think this is how Wittgenstein would have seen it.)

I have no idea how to remove the team in question from the game, or what the downsides of doing so would be. All practicalities aside, I'm interested in understanding how the above argument (syllogism and analogy) is refuted in principle (meaning philosophically).