>>reporter: governor baker maintained legalizing marijuana would pose a public safety threat, deaths of massachusetts state trooper thomas clarty who was killed when his cruiser was slammed into by a driver who prosecutors claim was under the influence of marijuana back in march. >> it's not just a legitimate concern for folks in law enforcement, it's a legitimate concern for all of us, and that's part of the reason why i'm voting no. >>reporter: jim vorgasani on the group yes on 4, actually would lay the groundwork for a safer system of marijuana sales >> how can anybody say that they want to maintain that dominated by people who don't check ids, who don't care how young their customers are, who don't pay taxes, and what we're saying is let's take that karma away from criminals and street dealers and cartels and put it in the hands of licensed, tax paying businesses. >>reporter: and he went on to call the movement, quote, a century in the making for massachusetts, while governor baker, on the other side, told us he plans to encourage people to take a pass on question 4, calling it, quote, a ba nick giovanni, wbz this mo