With just over two months to go until ballots are counted in Colorado’s primary, candidates are squaring off in high-stakes contests for their party’s nominations in statewide and congressional races approaching the midterm election.

For the first time in memory, state voters will have the chance to elect an entire new slate of state-level executive officials — from governor and attorney general to secretary of state and state treasurer — since those offices’ Democratic incumbents all face term limits.

At the same time, Democrats will decide which candidate to nominate in the state’s marquee U.S.…