I assure you Texas would not be able to support itself. It's culture doesn't allow it and it lacks the human capital and resources. It's got oil and gas. That's it. It's soil is unfarmable, it's mostly arid steppe. TX only has the 2nd biggest GDP in the U.S. because other states absorb a lot of the load TX would need to make up for as an independent country. Without Washington's support, TX is not the powerhouse you think it is.