Practicality. I.e., when the people judge that it is prudent either to do so, or not. And nothing else. That, too, is right there in the Declaration.
I remember.
The 1960s Marxist-Alinsky campus radical, psycho spoiled brats were celebrated in the establishment MSM as the most intelligent generation ever!. They are now arguably that very establishment that praised them and they hold themselves and their ideological issue in even higher regard.
You initiated a policy to tolerate the Marxist-Alinsky radicals and let them rant; not only has it not ceased but was constantly augmented by decades of infiltration and indoctrination. You now have two Americas. In my opinion, it will not cease until a crisis shall have been reached and passed. A house divided against itself cannot stand. I believe this government cannot endure, permanently, half statist and half free; I do not expect the house to fall; but I do expect it will cease to be divided. It will become all one thing, or all the other.