When your own founding document, the Declaration of Independence, specifically says that all states have a right to leave, it isn't "treason" when some chose to do so. It is the exercising of a fundamental right granted by God as detailed in the Declaration of Independence.
We have been over this again and again, and again, but ok. The Confederacy FORBADE States from leaving in thier own Constitution. Texas WOULD NOT have stayed in the Confederacy for long.