Delegate Selection Process
Both main parties hold a series of conventions to choose delegates for the next level convention, from the smallest voting area (the precinct) up through a county or senatorial district convention, and the state convention (and in presidential election years, to the national convention).
An overview of the process for selecting delegates of the Republican Party of Texas, from the Precinct Caucus on up is
here.
The Democratic Party of Texas follows a
process similar to that of the RPT, with one notable difference. Every level of the process is designed to elect a set of delegates that reflect the population in each area and to provide representation to a diverse population.