If you’re referring to the secessionist bit, basically no one (at least that I know). If you mean the keeping the Texas grid separate from the national grid, probably a fair amount as most conservatives will oppose anything related to the federal government. The best way I can sum up the sentiment is non-dependence rather than independence.

I’m 90% sure these exact lines, or something similar, is in the show. Edit: Nah, I just checked, the scene I was thinking of is completely different.