One thing I have found is that the most effective argument against these clowns is pointing out that all persons who serve or have served in the US Armed Forces have taken an oath to protect and defend The United States, and then I ask them if they expect these people to violate their oaths, along with inquiring into whether or not they have ever served. This is not some "left-right" political argument. Secession, and the advocation of secession, is treason and we should treat it as such. We should never fail to point that out to these crazies. The US Constitution has several ways in, and no way out, for states. The only legal way a state can secede is through Constitutional Amendment. If they claim some sort of right in some old treaty or whatever, it is usually a fantasy or typical right wing hoax-email legend. Simply tell them if they can get the consent of 2/3's of the Congress and a presidential signature, and the consent of 3/4's of the states, they can legally seceed, otherwise, they are traitors for advocating any other means, and will be subject to the oath taken by the men of our Armed Forces, who have pledged to destroy them, and not for the first time, either.