Lower the Legal Drinking Age to 18 in the U.S.

I believe the drinking age should be lowered to 18 in the U.S. because it's ridiculous to permit 18 year olds to do some things but prohibit them from doing other things. If 18 year olds are considered adult enough to vote, get married, get a job, join the military, purchase a car, donate blood, create a will, serve on a jury, adopt a child, and pay for their own health care, then it should be considered adult enough to drink alcohol moderately at 18.