DUI is already against the law whether marijuana is legal or not.
True. Also, the illegality of marijuana may actually incentivize its users to use it before they drive home, so as to minimize the length of time they're in possession.
Hey, I admit the druggie has won. We the sober will have to live with the consequences(Such as Colorado businesses having their workers show up wasted, the spike in accidents; the property crimes committed to get drug money etc. You druggies have truly achieved a great victory.