I never thought this should be legal:
"No Refusal Weekend refers to a short period of time, typically a holiday weekend or the weekend of a special event, such as the Super Bowl, where law enforcement advertises the ability to conduct routine traffic stops, detaining motorists for suspected DWI. During the stop, law enforcement requests a blood or breath sample, and, if the motorist refuses to comply, law enforcement immediately contacts a judge or magistrate who is designated “on call” during the No Refusal time frame. If the law enforcement officer conveys to the judge that (1) there was reasonable suspicion to detain the motorist for a traffic or criminal offense, and, (2) there is probable cause to believe the motorist is driving under the influence of
drugs or alcohol, then the judge quickly issues a search warrant for the sample. Tex. Transp. Code §§ 724.011(a), 724.012(b), 724. At that point, law enforcement may call for a phlebotomist to take the sample on site, or may transport a motorist to a facility to obtain the sample. If all goes according to plan, “no refusal” speeds up the process by which law enforcement obtain samples used for DWI/DUI arrests. Further, the sample becomes evidence for trial."
https://www.bhwlawfirm.com/no-refusal-dwi-texas/