Do DWI blood samples violate the 4th Amendment?

On January 9, 2013, the U.S. Supreme Court will hear arguments when law enforcement must obtain a search warrant to draw blood for a suspected DWI driver (Missouri vs. McNeely). If you are pulled over here in New York, you do have the right to decline a breathalyzer and to participate in field sobriety tests, but you will almost certainly be arrested and taken for a compelled blood draw if you are non-consenting. You will also lose your license and be ticketed for failure to comply.

In another case (Schmerber v. California), with only a 5-4 decision upholding a warrantless blood draw, the Supreme Court considered “special facts” such as an injury causing accident and held that limited intrusions on constitutional rights might be permissible but warned that intrusions under other circumstances might not be permissible. How do we consider what circumstances are permissible to disregard privacy rights? Should a routine, run-of-the mill DWI stop require a warrant? Courts have found that dissipation of alcohol in the bloodstream over time does not constitute an “emergency” or “exigent circumstances.” Although the blood alcohol level diminishes over time, it is not sufficient to force consent to a blood draw. Should an officer have to obtain a search warrant for these tests? Is there implied consent to them when you accept the privilege of driving?

What do you think? Does the public interest in preventing DWI outweigh privacy interests against unreasonable searches?