haha ya man, no offense but that ideas not very solid.
re-read what you wrote and break it down, your basically saying if people can smoke weed they will start doing coke, if we legalize coke people will start doing acid, if we legalize acid people will do heroine.
people dont smoke pot cause its illegal and cool. people smoke it cause they like it.
rape is illegal, people dont go around raping people cause its illegal and breaking the law is cool.
legalizing dope wouldnt at all mean your supporting the use of other drugs? and i highly highly doubt the niche for harsher drugs would go up. also, im pretty sure society and the government has a damn good idea of the consequences to every drug imaginable.
and mary-j isnt a harmless drug, it has many health risks, just like cigarettes, alcohol, junk food, tan in a box, and many other things that are legal because the government has found a way to tax it.
in my eyes weed will never be legal until the states says its ok. fuck police practically turn their back to it in canada cause they have better things to worry about like jeeze i dunno, murder? but will never be legalized because the states has this whole tight ass war on drugs thing going. there is no way canada being allies with the states can legalize a drug the states spends billions of dollars a year to try and criminalize and control.
and the only time the states will say it is ok is when they figure out a way to control it. think about what would go into making weed legal. it would either be sub-contracted to companies much like the tobacco industry, where independent companies can manufacture and sell pre-rolled or pre-packaged dope and the government taxes the shit out of it.
or, the government would have to manufacture and sell it themselves much like the medical mary j system right now. which will never happen.
so i wouldnt be crossing any fingers for legalization.
there are many arguments for why it should stay illegal, you just gotta thing outside the health and gateway drug box.
start thinking about things like impaired driving, how would they police it? drinking and driving is 0.08mL, what exactly is too high to drive? are they going to administer a road side blood test? who is going to fund these road side blood test? who is going to fund the technology for blood analysis? is it against a persons rights to legally force them to give blood under the suspicion of marijuana use? what if their not high, can they sure claiming bodily harm? what if their diabetic? what if their negative o blood type? what if they have aids, std's, etc etc etc
how about things like designated smoking areas? cigarettes are being more and more controlled in society and people must smoke outside buildings and atleast 100m from entrances to not disturb non smokers, so does that mean the weed smokers can smoke with the smokers? what about smokers who dont smoke weed? will the government make two separate designated areas outside all government buildings? install private building by-laws, bars, restaurants so on and so forth.
what about the possession of drug paraphernalia? having it isnt illegal, having it with marijuana in your possession is. so if they legalize dope does that mean i can smoke a bong while im driving? hit a vaporizer on city halls front door step? will rolling papers be government manufactured?
the key to winning your debate isnt to agree with the opponent. the idea is to come up with shit that will blow their fucking mind that if they had another week to think about the topic, they still wouldn't think of your specific point.
good luck