Governments are revenue whores.
Once the massive influx of people and money make Colorado Treasury coffers flush with cash, prohibitionists will get quieter.
Trust me, governors and other policy makers are keenly aware of which states are losing headcount and which are gaining--and why. People mean taxes and jobs. 20 somethings represent future high income earners that Colorado (one of the most educated states in the Union) and Washington will be sucking out of every state until those states adjust.
We vote with our feet.