After each census, districts have to be reapportioned based on new census data. In Texas, according to 2020 data, districts need to be around 766,000 in population to equally apportionment 38 seats. Ten years is the traditional length between redrawing maps to coincide with the census. In 1995 or so Tom Delay led the charge that made Texas the first state to restrict between census dates. Now, Abbot is bowing to Trump to redo Texas. It is a horribly political process that doesn’t have to be.
Several states use independent commissions to ensure districts are competitive, Arizona among them. I like fairness and equity. It would be nice to have districts drawn in a manner that actually made members compete for seats in the general election rather than be assured of victory after the primary.