How does Israel mange with only 8 million people? They have a country and an army.
>>Texas would flourish economically with the yoke of the federal govt gone. Only an idiot fails to that.<<
How? The USA would tell the world not to accept Texas scrip. The USA would take (or just not allow Texas to use) all military materiel. The USA would close the roads and into and out of Texas. It would blockade oil shipments and shut the pipelines at the border.
On day 2, things would get really ugly.
And that is just off the top of my head.
As I said the mechanics of a succession attempt would make a great book.