The Right has these delusional ideas of a glorious two sided battle, with a clear geographical line dividing the sides. That's the way they see the Civil War. But, there's really no such geographical demarcation in our modern union. Every liberal state has many conservative enclaves. Every conservative state has huge liberal enclaves (and they're usually the biggest cities with the highest industry and business concentrations).

Another civil war would be cities against cities, rather than one region against another region. Moreover, there are U.S. military bases in every state. These civil war redux folks don't seem to realize that all their guns would be nothing against the tanks and warplanes of the military. They're promoting a bloodbath.