A very strong case can be made that the use of marijuana is nowhere near as harmful as the use of alcohol. Yet it remains a criminal activity. A great illustration of the hypocracy of this situation is that politician after politician will admit to the use of marijuana in their younger years and simply shrug it off as "youthful indiscretion" or "experimantation". Yet they perpetuate the practice of locking up and/or fining and punishing others who are unlucky enough to get caught doing the same.
One argument for the continued criminalization of the use of marijuana is that it is a "gateway drug". The implication is that people who start using marijuana are more likely to eventually try other, more dangerous drugs. This may be true, but only because to access marijuana, at present, you have to go to a drug dealer. One could also make the case that marijuana is a gateway to criminal activity since to get it you have to engage in criminal behavior and patronize criminals. If one could buy marijuana at a bakery, it would be a gateway to increased doughnut consumption since the proprietor would invariably try to get you to make another purchase while you were there.
The "gateway" argument is a bogus one, since the gateway would cease to exist if marijuana were legal. Of course, driving a car on public streets or going to work inebriated should not be tolerated anymore than if you were to do the same drunk. But I don't believe people who imbibe in a little MJ during their Saturday afternoon barbecue are dangerous criminals. It's high time Americans took a long, hard, objective look at this situation. We need to stop throwing money down the black hole of marijuana use prevention. We can put the same sort of caveats on it that we do on alchohol.
The irony is, that if you buy the "gateway" argument, taking marijuana out of the realm of these gateways could actually reduce the use of more dangerous drugs as well as criminal activity by eliminating the need for customers to come in contact with those things in the first place.