The result of a 1992 referendum, backed by "Colorado for Family Values", a group featuring prominent leaders Dr. James Dobson and Coach Bill McCartney. It would have prohibited gay rights legislation (or "special rights", as CFV might have put it), and was a testing-of-the-waters (by the usual suspects, e.g. the Christian Coalition) for other such bids across the US. CFV won the referendum, but 2 didn't survive a court challenge, IIRC. Since when do we put people's rights up for a vote?