TX could have broken up into 5 States, had she chosen to AND could have reasserted her rights as a FRee & independent republic, according to many scholars in 1861 or NOW for that matter.
150 years of DAMNyankee/elitist domination does NOT change the TRUTH that the Constitution (particularly the 9th & 10th Amendments thereto) does NOT outlaw UNILATERAL secession. secession is still an option for EVERY State or group of States. furthermore, the States created the union & remain FREE to change/secede from/abolish that union at ANY time that they so choose.
free dixie,sw
This thus proves Mr. Lucky's point that no such provision or mechanism.