Just curious...
If people know they have a chance of getting arrested for drinking too much in a bar isn't there a chance that they might go to tailgate parties or somewhere else that they can get drunk with friends but don't have the option of calling someone for a ride so they won't have to drive?
SHHHH!!! Rather than realize the error of their ways, the nanny-staters will use your logic to start pre-emptively arresting people in their homes.