Rush Limbaugh may not be arrested, let alone spend time behind bars, for illegally buying narcotic painkillers. "We're not sure whether he will be charged," a law enforcement source told CNN earlier this month. "We're going after the big fish, both the suppliers and the sellers." If the conservative radio commentator escapes serious legal consequences, there will be speculation about whether a pill popper who wasn't a wealthy celebrity would have received such lenient treatment. Yet the distinction between dealer and user drawn by CNN's source is both widely accepted and deeply imbedded in our drug laws. That doesn't mean...