I just need to stay something from experience, so listen to me, as this has happened many times before.
The first year or two that Marijuana is legalized, everyone will jump on it. Sales will skyrocket, bad events from marijuana will skyrocket, potheads will skyrocket. The opposing news will use this as proof that it won't work.
But they're wrong... the sales, mistakes, bad events and potheads will soon drop an stabilize as people have gotten used to it, and the "cool new thing" vibe has dwindled.
Pretty much like a kid with a new toy... eventually he will settle down and use it less frequently and more carefully as time goes on.