There are a few groups standing in the way
1) DRug companies- Pharma companies do not want you growing your own medicine. They make medicine and then sell it to you at 7000% proffit. Medicinal MJ scares the shit out of them. They have spent millions of dollars lobbying government to tighten MJ laws. They have spent nothing, 0, nada on cocaine laws, meth laws etc etc etc. Kind of hypocritical considering there a now several companies manufacturing synthetic THC copies leagally. So we can make it in a labratory but not a garden?
2) Organized crime- These people have a LOT of money and have the added persuasion of violence behind them. They do not want MJ legalized and they fully support tougher MJ laws. In Canada, the government is trying to push through an archaic bill to make the growing of 5 or more plants qualify for mandatory minimum sentencing. This bill is overwhelmingly supported by organized crime up here. When your growing 2000 plants in a burried container, your already maximizing your risk, but a law like that just wiped out all your mom and pop competition, so now you can raise your prices (more perceived risk even though there isn't and less competition).
3) Justice Industry- In America the justice industry is out of control. Private prisons are the norm now and the industry is raking in record profits. The public portion of the industry (police, DEA, FBI etc) is bigger than ever. Over 10 percent of your population is now behind bars and the vast majority of that population is there for MJ related offences. This industry will fight legalized MJ to the death. Their jobs depend on it and so do their profits.
All three of those organizations have a ton of money and a ton of power and a lot of muscle in government.
A documentary called The Union: The business behind getting high is an excelent source of up to date stats and the reality of the current situation.
heres the trailer
http://www.youtube.com/watch?v=3HLzmH9VB6A
You think Marajuana will be legalized soon in North America? I dunno, we are fast approaching 1 million arressts per year in the US for MJ. WHat is the United States governemt going to do with millions of people in jail for a substance that is now legal? Open the cell doors and say sorry, please dont take it personally?