The laws regarding drinking and driving have been getting steadily stricter for the last several decades. At this point if someone gets a DWI they can pretty much count on having to spend thousands of dollars, going on probation, doing community service, and losing their license (especially if their blood alcohol content was considerably above the legal limit). The second DWI in a five year period means mandatory jailtime in almost every state. These penalties are harsher than virtually any other misdemeanor. So to answer your question: the laws have already gotten way tougher. It hasn't helped. Giving people years in prison for one DWI (where they'd be housed with truly malicious and violent criminals guilty of much more serious and premeditated crimes) is not a viable or reasonable option. Mandatory breathalyzers in every new car is an idea supported by some organizations.