18 is the age of adulthood in the United States, and adults should have the right to make their own decisions about alcohol consumption. Turning 18 entails receiving the rights and responsibilities of adulthood to vote, smoke cigarettes, serve on juries, get married, sign contracts, be prosecuted as adults, and join the military - which includes risking one's life.
Many countries with MLDA 18 have similar or better drunk driving statistics than the United States. Although the United States increased the MLDA to 21 in 1984, its rate of traffic accidents and fatalities in the 1980s decreased less than that of European countries whose legal drinking ages are lower than 21