What to watch: Voters in both parties will cast ballots on Tuesday in a primary that brings Colorado one step closer to determining who will succeed Gov. John Hickenlooper, a Democrat who is not running for re-election because of term limits. Read more

The governor’s race has highlighted the brisk pace of social and economic change in the state — which has legalized marijuana, passed gun control and seen home prices boom — and raised questions about whether this reliably purple state is turning blue.

The Democratic candidates include Representative Jared Polis; Cary Kennedy, a former state treasurer; and Mike Johnston, a former state senator. The Republican front-runner is Walker Stapleton, the state treasurer who campaigned as a firm supporter of President Trump.

— MAGGIE ASTOR