Quoting Chuck Bass:" No matter how you spin it, government needs money to run. Without money there would be no government ... [snip!] ... etc. So yeah, if a state were to secede, they would need to find a way to generate enough money to run their own government."
I was reading somewhere, don't remember where, someone said that if Texas left, OPEC better get used to seeing guys in cowboy boots and ten gallon hats. They have a long coastline, access to tons and tons of oil, and silver up in the panhandle. I really think they would do okay.