Texas wants to secede we should have these terms: No money, no SS, no medicare, no army, no nukes, etc. All SS paid in is forfeited by Texans. You're on your own.
So you would steal from people?
All federal lands remain owned by the US government (from a map it doesn't look like much).
A smart move would be for them to accept that term, and then embark on an endless series of negotiations to overturn it, but only after having established independence for a long enough period of time that people cannot claim they don't have it.
Besides, I think if Texas chose to seek independence, probably Oklahoma, Arkansas and Louisiana would join them. Possibly the whole thing could spread to much of the original confederacy, except for Virginia of course, because nowadays Virginia pretty much has it's tongue so deeply down the Federal throat.
I would expect that some of the western states might go too. Hard to say what would happen before.
Years ago I read a prediction by a Russian social scientist who claims the US would eventually divide up into five naturally occurring districts. He seemingly put a lot of work into his theory.