Never say never.
The price of freedom is eternal vigilance.
California used to be a red state. A long game of corrupting it from within was played, and now LA and San Francisco hold a permanent iron grip on state politics, keeping the state blue, despite the large areas of deep-red outside of those cities.
Do not think for a second that Democrats aren't trying to play the same long game with Texas to get a permanent, unassailable super-majority in Federal politics. The culture in large swaths of Texas might not be amenable to Democrat rule, but neither was the culture in large swaths of California. If Democrats can get enough control of enough of Texas's cities, they can corrupt Texas state politics enough to flip the state blue in Congressional and presidential elections.
It sounds fantastic and impossible, and Democrats rely on exactly that incredulity to play their long games.
Don't be complacent.