[Texaggie79]

An "underage" drinker also has property rights.

And he has the right to purchase beer, if the state he chooses to reside in views 18 year olds as mature enough to handle it.

[A.J.Armitage]

And he has the right to purchase beer, if the state he chooses to reside in views 18 year olds as mature enough to handle it.

No, he has the right to purchase beer, if he can find a willing seller. No one's rights depend on whether the government thinks he can "handle" it.