I voted never. I don't think the American people are ever going to wake up on this issue. In politics money drives everything. In this issue the main sources of funding against legalization comes from groups such as the alcohol industry and pharmaceutical industry. They both employ lobbyist and public relation companies at huge costs for a reason. They don't want/need the competition.
For example over the past 30 years, extremely vigorously for the past 10 or so, drug companies have been fighting against legalization of medical marijuana. Claiming the active agent in the plant, THC, has no medical value. All the while they've been developing a synthetic source of THC so they could market it. They now have that source, Marinol
http://www.druglibrary.org/schaffer/hemp/medical/marinol1.htm, and they’ve obtained FDA approval. They’re still paying big bucks to lobbyist to keep law makers from siding with the medical marijuana supporters and they still pay public relations firms big bucks to circulate the claim marijuana has no medical value. Now they’ve simply shifted their argument slightly to say “smoking marijuana has no medical value.” I hear that now every time one of these guy’s comes on the news and speaks about medical marijuana. They used to simply say the drug it self had no medical value. Now that they're selling monthly supplies of an edible, ingestible THC for $500-770 for a months supply. Suddenly it’s just the smoked variety that has no value. Never mind that a large % of medical users who grow their own also eat the stuff. They turn it into something called “Canabutter” and bake it into cookies and the ever popular brownie. The average citizen can grow a whole lot of the stuff for way less then $500-700 a month. But pharmaceutical companies are not interested in you being able to grow your own medicines now are they? And they’re willing to shell out huge amounts of cash to law makers to make sure that never happens.
So the cash will keep flowing and it will never be legal. IMO.