To understand why the answer is NO a person only has to look at Eastern Europe, the Middle East and even the European Union.
The smaller an entity is, the more vulnerable it is to invasion and revolution, subject to the whims of MAJOR powers, and the worse off it's economy becomes.
Why just Texas? Why not every county in Texas being it's own country? Or every town? Or what about my own house and property being my own country? Why can't I do that? Why not abolish all government and declare each person is their own country and their own nation?
Yeah, it sounds cool to some to say the Confederates should have had their own country, arguing some zealotry zippyhead head ideological slogans - pretending then reality MUST exist consistent with it because it is so philosophically corrrect.
It would be the coolness of Germany and Japan winning WWII cool or, if not, the USSR having come to dominate the world.
Historically, for thousands of years, none federalized regions were militarily defeated and, often, totally erased from history's future. EMPIRES can last a long time. Tiny countries do not.