Realistically, I would say all of the Dems are the worst. Each Dem has been advocating for government schools and never vouchers for leaving government schools. The Stapleton R guy is IMHO a GOP establishment person who will have support from the standard routine GOP types. Walker Stapleton does claim to be a supporter of Pres. Trump. In Colorado the GOP is a sad group of out touch clowns. Walker Stapleton may be the best choise. Part of the election depends on how much money will be spent from outside interests. Polis the Dem has got deep pockets. How much money will be spent on the GOP guy may determine who wins the election.