That’s a myth. Texas reserved the right to divide itself into five separate states. It did not reserve the right to leave the Union. IMHO, dividing into five states would weaken our influence. Furthermore, can you imagine any part of Texas opting to leave the Great State of Texas?
However, our rights come from God not the federal government. So, should Texas claim the right to leave the Union, the precedent was set with the Declaration of Independence.
North Texas, South Texas, West Texas, East Texas; who’s leaving Texas?