Oregon is one of the states that mails a Voter Pamphlet to each registered voter. The Oregon pamphlet includes a page for each party to explain its principles. However, this year, according to this story, the Democratic and Republican Parties failed to submit such a statement, so they are omitted from this part of the Pamphlet. Each of the five qualified minor parties did submit a statement.
Here is a link to the Table of Contents for the Voters Pamphlet. Click on the link for any particular party listed to read that party’s statement.