The real solution:  Make addictive drugs legal like addictive cigarettes and alchohol, and spend millions on anti-drug education and addiction treatment.  Any employer could still require employees to be drug free, and test.  Jobs involving public health, safety, and transportation could and should, of course, require drug free employees.

De-criminalizing drugs would cause the prices of banned drugs to plummet, thereby removing all motivation for cartel and gang crime.  The Taliban in Afghanistan would lose a significant source of their financing. We might start winning a real war.

And growers might find more useful crops more remunerative.