To determine that 10% of Americans effectively elected 83% of U.S. House Representatives in 2020, we looked at how many people participated in the election of consequence and whether or not that election was competitive. The “election of consequence” is the election that effectively elected the district’s representative; in competitive seats, this is the general election; in non-competitive seats, the dominant party’s primary is the election of consequence (i.e. the Republican primary is the election of consequence in safe red districts, and the Democratic primary is the election of consequence in safe blue districts). Further, primary elections are only considered “competitive” if there are at least two candidates to choose from.Given that most congressional districts are solidly Democratic or Republican, the general election is often a forgone conclusion: red districts will elect Republicans, and blue will elect Democrats. As a result, primary voters in the dominant party primary effectively decide the outcomes of most congressional races. We collected data on the number of votes cast for each candidate in every congressional district primary in 2020.
Learn more about what we found in our methodology deep-dive.