Oregon Legal Research Blog
Political parties are governed by federal, state, and local laws, but more to the point, they are controlled by their own party rules, bylaws, and traditions.
State and County political parties generally post their bylaws, rules, resolutions, and platforms on their websites.
The Oregon Blue Book section National, International and Tribal is a good place to start your research; it will link to statewide political party websites. Those websites will in turn link to local political party websites: