No, TX DA’s are elected, and Travis County has never had a Republican DA; it has had a Republican sheriff though.
Travis County's partisan DAs are just part of the problem.
The other part is Travis County grand juries. They tend to be populated by rabid moonbats who are all too ready to indict any Republican for anything, anytime.
Reportedly, one of the Delay grand juries voted to indict three minutes after the prosecutor brought the case.