Free speech is the unregulated speech of a free person. Free people become criminal when they engage in assault, which is what a threat on someone’s life is. And then those who threaten are open to prosecution.
Americans, of course, are too ill-educated to know what free speech is any more. Americans tend to think of “free speech” as all speech . . . minus those exceptions carved out somewhat arbitrarily by legislation and perhaps the common law (about which free speech absolutists shift in their seats when they acknowledge). But that is not the free speech idea.
Yes: free speech is a term of art. It refers to (and is made explicable by) a larger concept, liberty. Which depends on the basic decency at the heart of civilization, indeed, humanity: reciprocity. I do not get to initiate force against you, you do not get to initiate force against me. And a threat is considered an assault, an act of aggression. An initiation of force.
The only violent threats tolerated in common law are threats to retaliate. One has a right to self defense.
This is the great truth that libertarians emphasize, but almost no one else does: no one has a right to initiate force. That is honored in the breach, of course, in our government-ridden society, but more than acknowledged on the personal level in our law as applying to the person of the President. He is supposed to be constrained by our rights, listed somewhat crudely in the Bill of Rights, and he himself (like us) retains those common protections, plus an extra kicker bit of legislated law to back up his political station.
All those Anti-Trump assassination threats on Twitter? If the yobbos who made them continue, now they get to go to prison. And no rights would have been violated. Except Trump’s! But the prosecutors will be defending him.
Be assured, witless protestors and whiners, your days of license are soon to be over. Do you really want to test the system?