Major political parties in Oregon hold primary elections to choose candidates to represent them in general elections. Oregon law allows major political parties to decide whether to hold open or closed primary elections. In a closed party primary, only voters registered with the party holding the primary election can participate in its primary election. 

For the May 19, 2020 Primary Election, the major parties will be holding a closed Primary. If you wish to vote for the Democratic Party candidates or the Republican party candidates in the May Primary you must register with one of those parties by the voter registration and party change deadline, April 28, 2020. Voters registered non-affiliated or with a minor party will receive a ballot with non-partisan offices and ballot measures.

Partisan offices on the ballot in Multnomah County in the May 19, 2020 Primary Election (where only members of the Democratic or Republican party can vote on their major party candidates), include the following:

  • US President
  • US Senate
  • US Representative of Congress
  • Secretary of State
  • State Treasurer
  • Attorney General
  • State Senate
  • State Representative

Oregon’s minor political parties (see list below) each have their own method for choosing their candidates for the November General Election. 

There is no cost or membership fees to be part of a political party. You can change your party selection any time by updating your registration at or by filling out a new Oregon Voter Registration Card. However, if you want to receive a ballot for a major party’s primary election you must make changes to party selection no later than the Voter Registration and Party Change Deadline, 21 days before Primary Election Day. 

There are two major political parties and six minor political parties in Oregon. You can choose to be a member of a party, or you can choose to not be a member of a party (nonaffiliated).

Oregon's two major political parties are:

Democratic Party -
Republican Party -

Oregon's six minor political parties are:

Constitution Party -
Independent Party -
Libertarian Party -
Pacific Green Party -
Progressive Party -
Working Families Party -

​If you have questions or would like more information about closed primary elections and other elections processes:

Visit the Oregon Secretary of State’s website at or call 1.866.673.VOTE.
For Voter Education and Outreach support please contact Multnomah County Elections at 503-988-3720 or **The Voter Education and Outreach Program does not provide support at political events and is entirely nonpartisan. Multnomah County Elections does not endorse or discuss any particular candidates or measures.

Closed Primary Elections & Political Parties in Oregon (236.7 KB)