"I'm not sure the government is capable of regulating marijuana as it wants."
They sure as heck aren't regulating it now. They have zero control over it. All they are accomplishing now is seizing a couple of thousand tons a year and locking lots of people up at considerable expense to us taxpayers. Even seizing all they seize the last government estimate was that between 12,000 and 25,000 metric tons of marijuana were available on the market in 2002 as opposed to 10,000 to 24,000 that was on the market in the U.S. 2001. They're just throwing money away trying to stop this massive industry. Any control over it through regulation would be a lot more control than they have now.
I certainly wouldn't advocate smoking dope to anyone, but sending people to jail for having an ounce or less of the stuff is absurd.