Average turnout for presidential primary 2000 - 2020

Red counties have more Republicans registered to vote than Democrats while the reverse is true in blue counties. Party registration is close in Columbia County, with 11,443 Democrats and 11,565 Republicans, and in Marion County, with 60,262 registered Democrats and 60,823 Republicans.
Chart: Lynne Terry with John Horvick, DHM ResearchSource: Oregon Secretary of State's OfficeGet the dataEmbed Download imageCreated with Datawrapper