If you notice, the only people who get drug tested regularly are those in jobs without power or status. Watch what would happen to the ranks of professional athletes if there were serious drug testing. Half the teams would be disbanded. Heck, out here in California, they riot when the Lakers WIN. Imagine what they'd do if half the team got fired for drug use!
Or doctors. Drug abuse is rampant among physicians. Yet society has a vested interest in pampering them.
Do you think for a minute police officers unions would let them drug test officers on a regular basis, or more importantly, ever do anything about it if one were caught?
But let's continue to drug test grocery store employees and assembly line workers so we can pretend we are serious about the war on drugs.