Time was when leftists were latitudinarian to the point of extremism on the question of free speech. But of late a "sea change into something rich and strange" (Shakespeare, The Tempest) has occurred, the 'trigger' being the liberation of Twitter by Elon Musk. Leftists are now spooked by the specter of 'free speech absolutism.' And not only leftists, but certain of their pseudo-con fellow travellers such as the bootless Max Boot.
To discuss the topic sensibly we need a definition. One thing it should do is to specify that the topic is public expression, whether in speech or writing, not what occurs in private or in solitude. And let's be clear that the First Amendment to the U. S. Constitution protects speech against abridgment by the Federal government alone: "Congress shall make no law . . . abridging the freedom of speech, or of the press . . . ." (emphasis added) We also need to agree on what it means to say that a right is absolute. A right is absolute if and only if it is (i) inviolable (in the sense that it ought not be violated), (ii) exceptionless, and (iii) equal, i.e., the same for everyone.
Free speech absolutism, then, is the view that everyone has the moral right to express publicly, whether in speech or in writing, whatever one wants to express, on any topic, anywhere, and before any audience.
This is what I mean by free speech absolutism. (I also think that this is what everyone ought to mean by it.) Is that what you mean? There is no point in discussing this question or any question unless we agree on what exactly we are talking about. If you don't agree with my definition than you ought to provide and defend a different one.
Note that if the right to free expression is absolute, then whatever anyone anywhere expresses publicly to anyone, whether true, false, meaningless, incitive of violence, etc., ought to be tolerated. This follows from the correlativity of rights and duties. If the right to free expression is absolute, then the duty to tolerate is absolute and therefore exceptionless and the same for all. But then we get toleration extremism, a position defended by J. S. Mill which I demolish in an earlier Substack article.
Free speech and open inquiry must be defended, but no intelligent and morally sane person could support free speech absolutism. The speech-suppressive Left aided and abetted by cranky neo-cons such as the bootless Boot have created a bogeyman.