The law previously stipulated that, if the suspected drunk driver refused to take a breathalyzer test, the officer could ask for a warrant to have blood drawn. Now, the officer has total discretion on this decision with no judicial review beforehand. It's seems blatantly unconstitutional as unreasonable search and seizure to me but....again....as FOMM said, maybe things are different in here in Texas. Maybe we don't believe in the constitution down here. I don't think the legislature does, that's for damn sure.
Going slightly off topic this sort of reminds me of the change in the UK law made in 1994 with respect to your rights whilst being arrested by police officers.
When you are arrested now this is what is normally read out to you:
"You do not have to say anything. But it may harm your defense if you do not mention when questioned something which you later rely on in court. Anything you do say may be given in evidence."
Previously these rights would have been read out to you:
"You do not have to say anything if you do not wish to do so, but anything you do say may be used against you in a court of law."
Although the difference to the wording is only subtle, the implications can be huge in practice as the newer wording is specifically more aggressive in its stance, and erodes your civil rights in these issues.