Other than GOP dominance, what other factors would make it difficult for Texas to adopt a convention system of nominating candidates?
In my opinion, the main factor that would make it difficult for Texas to adopt such a system is one that is not unique to Texas. I think that it would be difficult for any state to adopt such a system because most people would think that it is antidemocratic.
Over the years, American elections have become more democratic. That is, we have constantly increased the number of people eligible to vote. This is because we believe that the people should have as much direct control over their leaders as possible.
To go to a convention system would be to go against this trend. We would be taking the choice out of the hands of the many and giving it to the few who attend the conventions.