Well, penalties increased and illegal BAC levels lowered. But those were the result of a change in public attitudes. "There but for the grace of god go I" was the prevalent attitude in the legal system, from police and prosecutors to judges and the people on juries. That made enforcement lax and defense verdicts common. Depending on the jurisdiction, typical first offense deal was a non-conviction slap on the wrist and a warning to "go and sin no more."
A number of factors led to the change. One of the turning points was a Massachusetts case in the 1980s (Irwin v Town of Ware). Drunk driver coming from a bar at 2 am stopped by small town police. They let him continue driving home with just a warning. He ended up killing three people in a head-on collision, including himself. At around the same time, Mothers Against Drink Driving was formed. Between MADD's efforts and cases like Irwin, societal attitudes changed at what I thought was a surprisingly rapid pace. And, as usual in the US, no middle ground. Over-tolerance straight to Zero Tolerance.
Think about it outside driving. Drunks - Dean Martin, Foster Brooks, Dudley Moore, Otis in Mayberry - were funny. Some will say some of their routines stand the test of time, but I doubt it would work well for someone starting out today.