About 43% of Oregon’s registered voters are unable to vote this May for the top candidates running for Congress, Oregon attorney general, secretary of state and treasurer. Even though these Oregonians meet legal qualifications for casting a vote, they will largely be shut out of those big-ticket races.

Why? Because the two major political parties want it that way.

Under state law, the state Democratic and Republican parties can choose whether to open their primaries to voters who aren’t registered with their party. They have rarely done so. And while California, Washington, Alaska and other states have changed their primaries to allow more voters to determine which candidates advance to the November election, Oregon lets the Democratic and Republican parties control admission to their nominating contests.

Taxpayers of all political stripes, of course, are still picking up the tab for the parties’ closed primaries.

This undemocratic approach has continued even with the adoption of Oregon’s “motor voter” registration system, which automatically adds newcomers to voting rolls as “unaffiliated” voters. According to April voting registration statistics, one third of Oregon’s voters — 1.1 million — are unaffiliated, easily outnumbering both Democrats and Republicans. Those registered to other parties account for nearly another 205,000 Oregonians.

So what can disenfranchised voters who want a bigger say in these races do? Change their registration.

Credit Oregon for at least making it fairly easy to change voter registration online. Voters can check their registration by going to the Oregon secretary of state’s voting resources page at oregonvotes.gov. They can look up their current information by clicking on the “Go to my vote” button and inputting their legal name and birth date.

From there, they can select “update registration,” enter in their driver’s license number and follow the prompts. Once they access their personal information, they can change the political party to either Democrat or Republican to receive a ballot listing that party’s candidates. The deadline for registration is April 30.

While voters still are limited in their choices — they can choose only the Democratic or Republican ballots as opposed to one listing all candidates — it’s better than being locked out completely. And voters can easily switch back to their previous status of unaffiliated, Independent, Green Party, Libertarian, or other after the primary.

The importance of voting in primaries is often overlooked, despite the consequential role they play in deciding our elected officials. A small percentage of voters is wielding an extraordinarily large amount of power. Shouldn’t Oregonians as a whole have a bigger role in determining the top nominees?

A state that truly walked its talk on voter access would not force people to even temporarily adopt a party in order to participate in the nominating contests for its top elected offices.

But Oregon is not that state.