The age was already 18 in most states, so that wouldn't have done anything.
The 21 age was chosen partly because there was already historical precedent in holding back certain rights or privileges until the age of 21, such as voting prior to the 26th amendment. Also, it helps that it's only 3 years from 18, so it can be written off as just a minor change.
As I mentioned MADD basically transitioned into becoming a neo-prohibitionist/temperance movement organization. Even the founder, who left the group the year after MADD succeeded in getting the National Minimum Drinking Age Act passed, believes that to be the case. Shifting the drinking age is one part of that, they've also campaigned for increasing the excise taxes on alcohol to reduce consumption.
The 21 age was chosen partly because there was already historical precedent in holding back certain rights or privileges until the age of 21, such as voting prior to the 26th amendment. Also, it helps that it's only 3 years from 18, so it can be written off as just a minor change.
As I mentioned MADD basically transitioned into becoming a neo-prohibitionist/temperance movement organization. Even the founder, who left the group the year after MADD succeeded in getting the National Minimum Drinking Age Act passed, believes that to be the case. Shifting the drinking age is one part of that, they've also campaigned for increasing the excise taxes on alcohol to reduce consumption.