The Texas legislature has given judges and juries broad discretion in assessing punishment, especially for 1st Degree felonies. If you’re convicted of a 1st-degree crime and have no criminal history or enhanceable aspects to the offense, you face anywhere from 5 to 99 years in prison.
This can lead to unfair discrepancies in sentencing for defendants that commit the same kinds of crimes. Sometimes the personality and history of the person on the bench ends up being more important than the facts of the case (e.g. is the judge a “hard nosed” ex-prosecutor, a former civil attorney with sympathies for those with substance abuse problems, or a women’s advocate who absolutely hates family violence cases). And, if you’re going to the jury for punishment, it’s basically a complete wildcard.
Texas repeat offender statutes complicate matters. If you’ve been consecutively convicted of two prior felonies, the prosecutor can indict you as a habitual offender. Upon conviction, your minimum prison sentence is 25 years.