1) The author argues that the legal drinking age in the US should be lowered to 18 from 21. They believe it is contradictory for 18 year olds to be considered adults but not be allowed to drink alcohol.
2) The drinking age has changed over time due to various acts, most recently being raised to 21 nationwide by the National Minimum Drinking Age Act signed by President Ronald Reagan in 1984.
3) The author plans to dispute the view that a drinking age of 21 prevents binge drinking among teens, claiming that lowering it could prevent unsafe binge drinking by allowing social drinking at bars instead of secretive drinking among peers.