No, you CAN refuse by the 4th amendment.
Now you might not like what happens if you do (automatic license suspension), but you CAN refuse.
If you refuse and they illegally take your blood, they should be sued for all they are worth.
I may go driving around Dallas NOT drunk and see if I get an offer I CAN refuse.
Is that Texas law?..... They now have this set up where they get a warrant and draw your blood like it or not. They have it set in a centeral location, judge on duty, nurse to draw the sample, etc. The refuser is brought in, the warrant is issued, the nurse draws the blood sample and the offender is processed..
Do you know that the above isn’t the procedure?