I honestly think the best america can shoot for is a de facto legalization through medical marijuana, because there is a nations treatise,
Single Convention on Narcotic Drugs, 1961. And that one is not likely to change for longer than you can imagine, the next meeting to discuss drugs will be in 2019 and even then it will not change either.
People should stop splitting into different groups like pot legalization groups, pot decriminalization groups and medical pot groups, instead they should come to a conclusion on what is more likely to pass based on laws and technicalities, because begging for it won't make it happen.