Responsible drug use is as much of an oxymoron as responsible road rage. You don't have to be the nation's drug czar to know that drugs loosen inhibitions and inhibit thinking. They make some people lazy and others crazy. Crack stimulates violence and paranoia. Heroin addicts have a hard time holding down jobs.
Pot heads tend to be listless.
I don't know anyone who believes that legalization will result in a decline in consumption. If some people are willing to risk substantial penalties to puff, snort or shoot up, imagine how many more will enter the drug scene when cheaper narcotics can be indulged risk-free. Health care costs, crime rates, domestic violence, joblessness - all would soar. The war on drugs is costly, and worth every cent. Ask the father of a child who's died from an overdose.