No, you come back.
If someone is operating a vehicle on a federal highway while they are stoned, I think that is the government's business.
But giving pee tests to every adolescent is not the government's business.
If a lot of kids are driving around under the influence of drugs and killing people (like happened in my town last year), it IS the government's concern. (Just like snipers walking around killing people is the government's concern.) There's still space for you in this universe...but it's a long way back...