General Legal Advice
Intoxication vs. Drunk
Drinking and Driving is not illegal. However, Driving while Intoxicated is. You don't have to be DRUNK to be intoxicated. You don't even have to have a .08 BAC (blood alcohol content) on a blood or breath test.
The State of Texas defines intoxication as having a breath or blood test of .08 BAC, or having lost the NORMAL use of one's mental or physical faculties (abilities) by the introduction of 1) alcohol, 2) drugs (whether illegal or prescribed) or 3) a combination of 1 & 2.
While a BAC must be proven by scientific evidence. The second is only based on an Officer's opinion. While you may be arrested and charged, all is not lost, as the State still has to prove the allegations, via admissible evidence, Beyond a Reasonable doubt!