Proposition 131 would change Colorado’s election system in races for governor, Congress, other offices

Proposition 131 would fundamentally change how many of Colorado’s elections are run, presenting one of the most sweeping changes to the democratic process in the Centennial State’s 148-year history.

As it stands, Colorado’s elections are generally handled in much the same way as in other states: In partisan contests, Republicans compete against Republicans and Democrats against Democrats in June primary races. A single winner from each party advances to the general election, where they’re matched up against any unaffiliated or third-party candidates who make the ballot. Voters select their preferred candidates, and the candidate with the most votes wins.

This ballot measure would upend that system amid a broader national push to pursue open primaries and ranked-choice voting.

The measure is backed by Denver millionaire Kent Thiry, the former CEO of dialysis giant DaVita, plus Unite America, a national group he co-chairs, and a small group of similarly wealthy donors.

It’s an initiative that was petitioned onto the ballot, and since it would change state law, the measure needs a simple majority to pass in the Nov. 5 election.

What would Proposition 131 do if passed?

Prop. 131 would change elections for the state legislature, state offices — governor, attorney general, treasurer, secretary of state, the State Board of Education and the University of Colorado Board of Regents — as well as federal races for Colorado’s seats in the U.S. House of Representatives and the U.S. Senate.

The measure would do two main things for those elections. First, it would replace the state’s current primary system with a single open primary in each affected race. That means all candidates would compete against each other in a primary, regardless of party. For example, there could be five Democrats, three Republicans, a Green and a Libertarian running for governor, all on the same ballot — and all considered by voters of any or no political affiliation.

The top four vote recipients in that primary — again, regardless of party — would then advance to the general election. (If only two or three people run in the primary, they all would advance.)

That’s where the second change comes in: Prop. 131 would institute a ranked-choice voting system, under which voters in the general election would rank each candidate in a given race by preference.

If no candidate earns a majority on the first tabulation, then the candidate with the fewest top-rankings is eliminated. Any ballot that had that candidate as the top choice then automatically shifts to that voter’s next-highest-ranking candidate, and the tabulation begins again. It continues in rounds until one candidate secures a majority of active votes.

If there are three or four candidates in the general election, voters don’t have to rank all of them; they may rank only as much as they wish. There is, however, a risk that their ballot will become inactive if all of their ranked candidates have been eliminated, since their votes can’t be reallocated.

When would election changes take effect?

That’s a trickier question to answer than you’d think. The ballot measure says the reforms would take effect on Jan. 1, 2026. But a late legislative amendment this year — inserted quietly into a broader elections bill at the end of the regular session in May — now requires that 12 counties use ranked-choice voting before it can take effect for statewide or federal races.

It’s unclear if and when that requirement would be met.

Gov. Jared Polis, apparently unaware of that amendment when the bill was passed, still signed the broader bill in June after the change had garnered media coverage. But he told lawmakers that if voters approved Prop. 131, he would issue an executive order to convene lawmakers and stakeholders to map out an implementation process. His stated commitment is to make sure the changes are in effect by the 2028 election cycle.

That still would be two years later than the ballot measure stipulates, and it would mean the new system wouldn’t be in place for major races in 2026, including the first open gubernatorial race since 2018.

What do supporters say?

Supporters of the measure pitch it as a broad balm to a variety of ills plaguing America’s elections. They argue that an open primary system would allow voters of all kinds to have a more direct say in choosing general election candidates, particularly in places — like Denver — where one party’s primary now generally decides who wins the general election in November.

They also contend that ranked-choice voting, the second piece of the measure, would empower voters in all districts to have an influence on who wins, while bolstering the chances that the ultimate winner has secured a majority and is a consensus choice.

Supporters also argue that the reforms would increase civility because candidates of different parties would be incentivized to appeal to voters of all stripes; improve turnout because races would be more frequently contested; and improve candidate diversity because the fear of “spoiler” candidates would be eliminated.