It's a brave person who registers as an independent or worse is unaffiliated. For one thing they cannot vote in closed primaries, which applies to Oregon.
"More than 800,000 of Oregon's 2.6 million voters are not registered with any party. That's fewer than the number of registered Democrats and more than the number of registered Republicans. Only voters registered in either party can vote in the primary, which chooses candidates for the general election." The Oregonian