You can register with a political party.
Political Parties in Oregon
Major political parties in Oregon include the Democratic and Republican parties. Statewide minor political parties include the Constitution, Independent, Libertarian, Pacific Green, Progressive, and Working Families parties.
More detailed information, including officers, can be found at the Oregon Secretary of State’s website.
Democratic Party of Oregon
Independent Party of Oregon
9220 SW Barbur Blvd, Suite 119-254
Portland, OR 97219
Contact form: https://www.indparty.com/contact
Working Families Party of Oregon
PO Box 38
Woodburn, OR 97071
Email: hello@owfp.org