They sure are setting up the debate in the proper manner. Let Texans debate it for themselves.
I favor extending the right to secede on a county by county basis.
The invitation could even be extended to counties in Mexico and Canada, since we are starting a new country.
Let there be a referendum within each countyfor the next 4 or 5 decades, let each county decide for itself and let the boundaries solidify. Dual citizenship for both sides for those 5 decades.
There are already sovereign nation enclaves within the borders of the US, they are called Indian Reservations.
Great idea, though it would be a real nightmare if the territory was not contiguous. With Colorado, new Mexico, Arizona divided by blue extclaves they would have to get passports to travel to other gimmiedat areas. Interesting to note how few blue counties have airports. Most are in adjacent counties.
Most of the oil/gas and other resources (such as most farming) would be deep in red country. This includes Mexico and Canadian areas.