Independent Party of Oregon STAR Voting Primary: Spotlight on the Data

STAR Voting
3 min readJun 6, 2020
STAR Voting Presidential Preference Poll results: Biden and Trump advance to runoff. Biden wins with 55.1% of the vote.

Joe Biden and Donald Trump, the two highest scoring candidates, advanced to the automatic runoff. Biden was preferred by 55.1% of voters; 39.4% preferred Trump. 5.5% had no preference between Biden and Trump.

Vote Splitting Avoided:

With another voting method, the Independent Party of Oregon Presidential Preference Poll could have been a perfect storm for vote splitting.

Here’s a look at voters’ favorite candidates only:

  • 38.3% preferred Trump
  • 35.6% preferred Biden
  • 22.9% preferred Sanders
  • 3.1% had two candidates tied for favorite

The election featured three candidates, but only two political parties: Donald Trump as the Republican and Joe Biden and Bernie Sanders as the two Democrats. With Choose-One voting the scenario would have been predictable. Sanders (who has suspended his campaign) would likely be the spoiler, drawing enough votes from Biden that the Democrats would both lose, despite being collectively preferred by a majority of the electorate.

With STAR Voting, vote splitting was avoided. Voters were able to score their candidates, showing both their level of support for each, and also their preference order. For each voter whose favorite wasn’t ultimately viable, assuming they had a preference between the finalists, their vote went to the finalist they preferred.

Voters took advantage of the expressive ballot:

  • There were three races in the Independent Party of Oregon Primary, including the Presidential Preference Poll. When we look at expressive voting across all three, 61.9% of voters gave scores to multiple candidates (440 voters).
  • When we look at data from just the presidential preference poll, 44.9% of voters gave a score to more than one candidate, while 55.1% expressed support for only their favorite.

For polarized voters who only like their favorite and who dislike the other party’s candidates equally, simply giving 5 stars to your favorite is an honest vote. For voters who are not worried about vote splitting, there is less of a need to show preference order or secondary support for candidates from other factions.

Conversely, for those who are worried about vote splitting in their faction, or who are not confident that their favorite can win, the incentive to be expressive increases.

The Presidential Preference Poll had two Democrats running against one Republican. In races like this, where the field is lopsided, it makes sense for the faction most at risk of vote splitting, or of wasting their votes, to be the most expressive. This is in fact what we saw when we broke down the data on voter expression by preferred presidential candidate.

Voters who preferred either Democrat were significantly more likely to give a score to at least one other candidate. While only 17.6% of voters who preferred Trump also scored another candidate or two, a full 52.7% who preferred Biden chose to score one or more additional candidates. Voters who preferred Sanders, the underdog in the race, were the most likely to show their second choice: 81.3% of them scored one or more other candidates.


  • Voters in this three-way race were able to show secondary preference as needed, which allowed them to avoid a spoiled election.
  • Joe Biden was preferred over Trump by a true majority.
  • Sanders voters elected their second choice.
  • Based on the Trump voters who did express a preference between Biden and Sanders, Trump voters as a whole may not have preferred either Democrat over the other in this race.

In this election, if Trump voters had shown a secondary preference for either Biden or Sanders it’s unlikely that this would have changed the outcome. Nonetheless, Trump voters who would have preferred Sanders will be incentivized to be more expressive in future elections.



STAR Voting

The incentive and ability to vote honestly: STAR Voting is the first step to ending two party domination.