I keep trying to help people see how futile it is to create a primary model for Texas since there is no party registration. Here’s an example from Hidalgo County in the Rio Grande Valley. There were over 58,000 Dem primary voters and only 18,500 Rep. That is a D+52 split. Trump won Hidalgo by 3 points - first GOP win since Nixon. In these South Texas Hispanic counties, which have only moved hard right in the last six years, there still isn’t much traditional GOP infrastructure and there sure as hell aren’t many neighborhood ladies’ republican clubs. Just about every local office imaginable all throughout the Rio Grande Valley is run by a Democrat. Those are Dems like Henry Cuellar, not psychos like the ones shooting heroin in Austin. If you want a say in local politics then you still draw a Dem ballot. Until the GOP makes permanent inroads there, that will be the way it is. But you should also know that people making models using primary share may be technically correct, they are functionally wrong by not explaining this important FACT that such counties will run hard to the right of their primary participation splits.