The crack in your argument that I see is that the splits that led us to where we are now are fundamentally cultural, with ethnic tensions added by the left to divide and conquer the country as a whole. Just as Attorneys General from 26 states banded together to take Obamacare to the Supreme Court, so it will be with secession.
Where Texas goes, so Arizona goes, and Oklahoma, Mississippi, probably Lousiana, Alabama for sure, Georgia and on and on. The problem the Left has is that culturally, the Red states, especially in the South, have a much stronger culture with respect to family, education, work and productivity, and obviously tax revenue generation than bankrupt Blue states like California, Michigan, NY and NJ. The blue states have a much higher percentage of unions, parasites and suck much more of fed revenues than the red ones.
The discussion of secession is not one the Left would want to engage. Their whole existence is dependent on dependents. Look at our own American Revolution to see how the power of the will for freedom and self-determination by the productive class overcomes overwhelming adversities. The dependent class is not suited for such a fight. No discipline, no culture, just pitiable dependency.
I actually think that the GOP will be the bigger problem in a secession scenario. TX has 38 electoral votes. If those were to go away, it would mean permanent minority status for the GOP.