All of this is irrelevant.
It's none of the governments business whether or not people smoke MJ.
The government has no right to tell you what you can and can't do with your body. Just because a right isn't enumerated in the constitution, doesn't mean the right doesn't exist.
You absolutely have the right to treat your body however you want.
Anyone who says you should have the freedom to own a gun, but not to smoke a plant, is a hypocrit. Pure and simple.