The 1904 United States presidential election in Oregon took place on November 8, 1904. State voters chose four electors to the Electoral College, which selected the president and vice president.
President Roosevelt was extremely popular in Oregon because of his policies of reforming the railroads, creating a Department of Commerce and Labor and conservation of the forests that were at the time heavily exploited by large businesses. Parker's re-emphasis on the Gold Standard, which harked back to Grover Cleveland, aroused little enthusiasm in Oregon. Nor did his opposition to Roosevelt's policy of imperialism in the Pacific, with the result that Parker's showing was the worst-ever by any major-party nominee in Oregon except for his mentor Cleveland twelve years previously. At the same time, Roosevelt's performance remains the best ever by any presidential candidate since Oregon's statehood in 1859. Parker did not win more than thirty percent of the vote in a single county, and overall took just a little over nineteen percent of Oregon's ballots, 18% below his national result and a 20% drop from Democratic performance in 1900.
Socialist nominee Eugene V. Debs, whose campaign focused on trust-busting and the opposition to monopolies, traveled all around the nation in a charismatic campaign that netted him over four hundred thousand votes nationwide. Although he did not outpoll Parker in any Oregon county, Debs nonetheless received over eight percent of the vote, 5.5% higher than his national performance.
This election would solidify Oregon as a one-party Republican bastion, which it would remain at a presidential level, apart from the 1912 Republican-progressive split, until Franklin D. Roosevelt was elected in 1932. After this election, Democratic representation in the Oregon legislature would never exceed fifteen percent until 1954, with the exception of a brief period in the 1930s and no Democrat other than Woodrow Wilson would henceforth carry even one county in the state until the Great Depression. Republican primaries would become the chief mode of competition: indeed Oregon became in this election year the first Western state to utilize the direct primary.