Never mind on Colorado ever being even remotely competitive if this happens. Alaskans might also get pissed off--all these amazingly enlightened policy moves.
If they actually end up taking an aggressive stance towards legalization, it could pay dividends for Colorado Democrats. Besides the Democrat-controlled Gov office, there are 3 GOP-held executive offices up in 2018, the State Senate, 1-2 House seats that would be potentially be in play and then in 2020, Gardner's Senate seat.
Someone in GOP leadership should try and talk him out of anything bold on this front. It's not worth it. America has turned sharply in favor of medical/legalized marijuana.