Have they always not allowed voting by the people? I wouldn’t like that.
Colorado had a presidential primary for a few cycles starting in 1992. They turned it over to party caucuses to save money from the state budget, and the parties didn’t mind because caucuses can give a state more political clout.
I've been told by party insiders that they used to have voting by the people; but they switched to the caucus system because everyone thought things would work better if the "most active party members" (euphemism for "insiders") decided everything. This was before I moved to the state.
It's despicable. I can hardly believe this shameful process still exists.