If Texas decided tomorrow they were seceding, Abbott and everyone else involved in that decision would be hogtied and presented to the feds within the week after

1. Every electric plant in the state was bombed. This works because TX has its own grid to dodge fed rules. Hence why it fails in winter because capitalism means fuck safety rules.
2. Every credit and debit card in the state stopped working, along with likely every bank account, which is vaguely related to 1 but also for its own reasons.
3. Every grocery shelf went bare. We saw what COVID did.

In a smart system, they'd try everyone involved and lock them all up for life and the incident would serve as a reminder that if you fuck around you will find out. Of course with our luck we'd get some dipshit president to fuck up that bit just like after the civil war