The problem is that Dallas (and other areas) have been sucked dry of talent by tech companies for a while - even before the conservative economic policies you're handwaving about came into effect. Some of that is on the state for not being competitive enough, other parts of that have been on predatory practices by businesses that fuel things like state to state income inequality.
Second, I don't need to be told what to be afraid of, so your condescending tone can take a listening stance. A software engineer in Dallas Texas doesn't make near the cost of living difference between a San Francisco job while doing the same thing and that is a problem. Full stop.
That problem can be remedied by bringing more tech businesses to Texas and gating them out of the traditional coastal areas like New York, SF, Seattle, and Portland. There are other ways of remedying the problem and I'd love to hear them, but finger pointing at the Texas government without pointing at companies and other states sounds pretty fruitless.