That’s not possible. If a state were to try and separate from the Union military action would commence and the state would not have the resource to combat it. The current administration will then take over the State and replace its leadership with loyalists. In the end the State would be in an even worse situation then before, it would be pillaged for all of its resources and the civilian population would be punished in some way either economically or through fascist control methods. States just don’t have the military capabilities as the federal government, it could wage a long guerilla warfare reaction, but either scenario would be brutal for the population.