If Texas secedes, its government, taxing structures even its money systems are open to radical change. The welfare bennies that the Mexicans come to Texas for will be gone and Mexico has two nations it needs to deal with on its border. The state won’t turn blue because it is no longer a state but its own nation...even its political party structures will change since they will be suject to the NATION of TEXAS...not the state of Texas. Mexicans who were not citizens of the US, will not be citizens of the nation of Texas unless they agree to adopt to its new constitution and laws...otherwise they can be forcibly thrust over the Mexican Border with no interveneing courts or ICE interference to say them nay!
There is no down side to Texas becoming a nation again.
The state of Texas votes Republican because it doesn't agree with what Northern liberals want to do. Take those Northern liberals out of the picture and what Texas voters want to do will change.
I wouldn't be surprised if an independent Texas looked more or less like the country it decided to leave. That's what happens. Given enough time, independence movements make government stronger, rather than weaker. We revolted against Britain and the taxes Parliament imposed on us and developed a government that taxed us more than the British ever did.
People just love to look at the CSA as though it were some anti-government movement, when it was a government that was at least as repressive as any other American government. Ireland revolted against England to go its own way in the world, but decades after British influence were thrown off Ireland is more European and less "Irish" than it was in the past.
Maybe I'm rambling, but politics has to do with a balance of forces and tendencies. Remove one force and you'd be surprised what the new balance will be. When the welfare state isn't seen some alien Northern thing, Southerners or Texans might take to it more than a lot of people think now.
So you’re on for the bet?