The driving force was under the affect: Evidence need to show the driving force was impaired, typically through a blood alcohol concentration (BAC) of 0.08% or better or evidence of drug impairment. Criminal legal guidelines vary from state to condition, as do prison punishments, but felonies have a weighty penalty: https://dui-lawyers.usattorneys.com/texas-appeals-court-repeat-dwi-offender-must-serve-life-in-prison/