The Short Answer: No Majority Needed
For general elections, Oregon does not require a candidate for federal office—that includes President, U.S. Senator, and U.S. Representative—to win a majority (more than 50%) of the vote. Instead, Oregon uses a plurality voting system, often called 'first-past-the-post'. In this system, the candidate who receives the most votes wins the election, even if they fall short of a majority. For example, if three candidates are running and the votes are split 45% for Candidate A, 40% for Candidate B, and 15% for Candidate C, Candidate A wins the election despite nearly six in ten voters choosing someone else.
Plurality Wins and the 'Spoiler Effect'
This first-past-the-post system is the most common method used in the United States for federal elections. It's straightforward and decisive.
However, it’s also the system that gives rise to the 'spoiler effect'. This happens when two or more ideologically similar candidates split the vote, potentially allowing a less popular candidate to win with a plurality. Voters may feel compelled to vote strategically for a 'lesser of two evils' candidate who has a better chance of winning, rather than for the candidate they truly prefer but who is perceived as having no chance. This dynamic can discourage third-party and independent candidates who worry about siphoning votes from a major party candidate they generally align with.
What About Primaries?
Oregon's primary elections for federal and state offices also operate on a plurality system. The candidate who gets the most votes in their party's primary moves on to the general election, regardless of whether they secured an outright majority. This is different from some other states, particularly in the South, which hold runoff elections if no primary candidate achieves a majority. In those states, the top two vote-getters face each other in a second election to ensure the party's nominee has majority support. Oregon's method is simpler but means nominees can, and often do, emerge from crowded primary fields with a relatively small percentage of the vote.
How Other States Ensure a Majority
While Oregon sticks to the plurality model for statewide and federal races, other states have adopted different systems to ensure winners have broader support. Georgia and Louisiana, for instance, require candidates in general elections to win a majority, triggering a runoff between the top two if no one exceeds 50%. More recently, states like Maine and Alaska have implemented ranked-choice voting (RCV) for federal elections. In an RCV system, voters rank candidates in order of preference. If no one wins a majority of first-choice votes, the last-place candidate is eliminated, and their supporters' votes are redistributed to their second-choice candidate. This process continues until one candidate secures a majority.
The Push for Change in Oregon
There has been a significant movement within Oregon to adopt ranked-choice voting. Proponents argue it reduces negative campaigning and ensures winners have broader consensus. Local jurisdictions like Benton County and the city of Portland have already adopted RCV for their elections, with Multnomah County following suit. A statewide ballot measure in 2024, Measure 117, proposed implementing RCV for federal and top state offices starting in 2028. However, voters ultimately rejected the measure, meaning the first-past-the-post system remains the law of the land for federal elections in Oregon for the foreseeable future.
