Seventy percent of 600 registered Oregon voters surveyed by DHM Research said voters should be able to participate in primary elections regardless of party registration. The poll was conducted Sept. 24 through Oct. 1 and has a margin of error of plus or minus 4 percentage points.

Oregon currently has closed primaries: voters generally receive the ballot for the party with which they are registered. The state allows major parties to open their primaries to unaffiliated voters, but neither the Democratic nor Republican party has chosen to do so.

Katrina Gill, a 58-year-old Cornelius resident registered as a Republican, said the rules mean she can’t choose a different party’s ballot in May, even when she prefers another party’s candidates. She favors being able to switch between primaries.

Support for broader access crossed party and demographic lines in the survey, though it was stronger among Democrats than Republicans: 73% of Democrats and 50% of Republicans backed the idea. Support reached 77% among nonaffiliated voters and people registered with smaller parties.

That majority does not necessarily translate into agreement on a specific reform, said DHM Research pollster John Horvick. Voters may worry that a change could give one party an advantage or leave a party without a candidate in the general election, he said.

Oregon voters have rejected open-primary proposals twice, in 2008 and 2014. Both would have put candidates on one primary ballot, with the top two advancing to November regardless of party. A proposal to require a top-two system through a constitutional amendment stalled in the Legislature this year, while two initiative campaigns did not qualify for the November ballot.

The debate comes as the state’s registration mix changes. Since Oregon Motor Voter took effect in 2016, eligible people interacting with the state’s driver and motor vehicle services have been automatically registered unless they opt out. They are listed as nonaffiliated unless they select a party.

Nonaffiliated registration has risen from about 680,000 in November 2016 to more than 1.15 million this September — a nearly 70% increase, according to the Oregon Secretary of State’s Office. Democratic and Republican registration has remained essentially flat, leaving nonaffiliated voters as Oregon’s largest registration group.

Oregon voters can change party affiliation, but must do so at least 21 days before a primary to receive that party’s ballot. Texas, where poll respondent Kenneth Pricer previously lived, does not register voters by party and lets them choose which party’s primary to vote in each year. Pricer, now a Democrat in Medford, said he has come to value that flexibility.

Other voters see value in keeping party primaries limited to party members. Scott Morris, a 62-year-old Portland carpenter, said party affiliation can encourage voters to engage with a group whose priorities they share.

States use a range of primary systems, from allowing unaffiliated voters to choose a party’s ballot to placing candidates from all parties on a single ballot. Oregon’s poll results show substantial interest in changing who can participate, but the state’s past ballot defeats and unresolved concerns leave the path forward uncertain.