Quick googling let me know there are about 10 million households in Texas and 40% of those have at least one gun. Lets say that transfer to one gun owner per household. 4 million gun owners in Texas. Lets say 2% of those show up to die. That's gonna be a great army of 80k.
Assuming these bumbling fools will be about as effective as Russians in Ukraine, they will have a mortality rate of about 431 dimwits a day. I would say this is generous, considering what they would be up against.
If they fight to the last man; they will last about 185 days. Though it is unrealistic they would fight to the last man. lets say they capitulate after 20% losses. That hypothetical conflict would last about a month.
I would like to believe they would just get cold feet before any violence sets in. It's easy to talk tough on social media, but when cold reality washes over them, they will do the smarter thing.
My numbers might be way off. It was just a fun little math exercise. Edit: I didn't take in to account that only about 39% of adults are republican voters.
Also a huge percentage of these meatheads would be unqualified to serve in the US military because so many are lardasses. There's a very good reason why physical fitness is taken so seriously in all of the world's best militaries; it's because actual combat is one of the most physically demanding and exhausting activities there is.