I think that the US should keep the current age restriction on alcohol. I do agree with Alex saying that teens drink today are drinking, but however this fact is not a responsible argument as to why they should lower the legal drinking age. If we lowered the legal drinking age from 21 to 18 this would cause an enormous increase in the amount of of teenagers who drink.
Teenagers are irresponsible, don't know how to handle emotions and feelings, and tend to think they are invincible. Think about what this will do to society; more health problems, a very high increase in alcoholics, more car accidents resulting in death, affecting the academic performance, and much more violence. What if a student who is 18 decides to drink before arriving to class and becomes irritable or angry? All of his/her surrounding peers and teacher's safety is at risk. What if they have a friend who isn't legal to drink? I am positive that a whole lot more teens that today will start drinking because it'll be all the more easier to get it from their friend is only 1-3 years older than they are, and next thing you know you have a party of drunk teenagers.
I understand Alex saying that this is a freedom that the constitution cannot intrude on, but if we were to lower the legal drinking age there would be an uproar afterwards due to all the negative that will come of it. Lowering the legal drinking age will enable teens to commit suicide because surely it is a death sentence. Can you imagine a drunk teen texting and driving with someone in the passenger seat? I guarantee this will become to new epidemic if the legal age is lowered. Teenagers are not responsible enough to comprehend the consequences of drinking and to know how much is enough, all they will think is "Yay we can drink after a football game!" This is a horrible idea and will result in deadly consequences.