I live in Texas and lots of people were talking about that a few years ago. "We should just secede!", when i pointed out that they would have to defeat the United States Marines (and all of the United States armed forces) first they got real quiet. Once a state declares they're no longer a part of the United States then any sense of Constitutional protections or governance fly out the window. They're now on their own and subject to the full force of the remaining United States.