Not to worry, it has a better chance of happening 150 years from now, if at all, than it does any time in the near future. Like the tea bagging parties (snerk), these are a minority few whose views will not be gaining any traction in the majority public view. And even if they had, the federal government would not allow it, denying them by law and/or show of force. Take all the 2nd amendment protected small arms to the fight that you'd like, you may as well be shooting peas compared to the government's military might. There are no civil war comparisons to be made when you're talking about going up against a modern day superpower.
This is an interesting point, but I wonder how the world community would respond to the US denying a state secession. Look at the stance that has been taken over former USSR states, Taiwan, etc. ???
This is totally hypothetical because like you I don't think this kind of thing would ever really happen (at least not in my lifetime)