The effect you're describing is sometimes called "dummymandering", when you so strongly gerrymander your map that just a small shift in voter preferences can now swing previously safe districts. It would be awesome to see this anti-democratic acts bite them in the ass.
Thanks for the terminology. My first thought when Texas started this power grab was that reliably red votes won't be reliable. The margin won't be as safe as they used to be. My second thought is take nothing for granted.
I read about this even before they did it. Jasmine Crockett has already said that she'll run in another district, so the other Democrats will too. 😉