Actually, the feds haven't since the repeal of the 18th amendment. I know...never let that damned piece of paper get in the way of telling people how they are allowed to live their lives.
If you believe that the government doesnt have this power, why not permit a 14 year old to drink legally?
Why not? More importantly, why would you let your 14 year old drink if you believe it to be so terrible? I guess that law is the only thing keeping you from letting your 14 year old drink, isn't it?
Do you believe a 14 year old should be able to buy alcohol like she buys ice cream?