I'm sorry to potentially upset you, but that is the poorest argument for legalization. Claiming one thing should be allowed because other things are worse is never a good way of going about anything. To put it into some kind of perspective, would you tell a judge to let you slide for grand theft auto because rape and murder is worse? This was addressed by an opponent for legalization who said just because there are harmful substances out there, that doesn't mean you should add another-- a very good counter claim.

What you can do with that argument however, is make people aware that cannabis prohibition has little if anything to do with health risks. You can use this is very reasonable proof that cannabis is illegal because it would be a major threat to the tobacco and alcohol businesses.

Ultimately, you want to enlighten people as to do the benefits of cannabis not the harmful effects of other drugs .