This was the ninth presidential election in my lifetime, and the fourth in which we’re left with “minority rule”, that is, the winner of the election received less than 50% of the popular vote. Bill Clinton won with 43% of the vote in 1992 and with 49% 1996, both times due to Ross Perot pulling substantial third-party support. In George W. Bush’s 2000 win, he had 48% of the popular vote. While this year’s numbers aren’t yet final, current estimates have Trump with about 47% of the vote and that may drop another point or two as California’s absentee ballots are tallied.

While many focus on the role of the electoral college in these outcomes, I want to take a closer look at the role of the voting system itself. How might 2016 have unfolded under a different system, like Ranked Choice Voting, which prevents minority rule outcomes?

There can be only one

Our current voting system is typically referred to as “first past the post” or “winner take all”. The idea is simple enough; each voter gets a single vote which they cast for the candidate of their choice. But while this system appears simple and fair at first glance, over time it inevitably leads to a two party system with sharp polarization. This is true whether you’re electing American presidents or the King of the Jungle. Any candidate outside of the two major parties is a potential “spoiler” as they could disproportionately take votes from one of the two major candidates (see Nader, Ralph). Voters are left to choose between the lesser of two evils, not supporting their ideal candidate for fear that their least favorite candidate might benefit.

Ranked Choice Voting

Under a Ranked Choice Voting (RCV) system, voters don’t select a single candidate but instead rank all candidates on the ballot from their most to least favorite. When the votes are tallied, if no candidate has a majority then the candidate with the fewest votes is removed and their votes get redistributed among the other candidates based on each voter’s next best choice. This cycle continues until a single candidate has secured a majority. Proponents of RCV highlight that, among other benefits, this system eliminates the “spoiler” effect that third party candidates have under a Winner Take All system. Voters can rate their preferred candidate first without fear that it might aid their least favorite candidate.

RCV 2016

This year saw support for third-party candidates at the highest levels in decades and major party candidates with record low favorability ratings. What might have happened if there had been a broader field of candidates to choose from and an election run under RCV rules?

Fortunately, the Pew Research Center January 2016 Political Survey* asked some questions that let us investigate things in more detail. Survey respondents were asked to rate 9 presidential candidates on whether they would be a great, good, average, poor or terrible president. We’ll use these ratings as a way to approximate how the respondent would rank the candidates in an RCV election.

As an example; say a respondent said that Cruz would be a great president, Sanders would be good, Clinton would be average and Trump would be terrible. That respondents’ ranking would place Cruz first, then Sanders, Clinton and finally Trump.

Some methodological notes… In the case of a tie (e.g. a respondent thought that both Clinton and Trump would make an average president), I broke the tie at random. Candidates who were not rated or not known by a respondent were ranked the same as “terrible”. The Pew study was weighted to match the Census Bureau’s 2014 American Community Survey, so while the results are representative of the population, they are not representative of the electorate.

I’m the first to admit that this approach not perfect but I believe it should make for a reasonable approximation for how an RCV election held in January 2016 could have unfolded. I wish there were some true third-party candidates included in the survey, but oh well. Besides, Evan McMullin wasn’t even running until August!

Results in a January 2016 RCV Election

Remember January 2016? Simpler times… well, not really. Pew asked about 7 Republican candidates and 2 Democratic ones. Clinton and Sanders are in the top two spots, but really only because the Republican field is so big. Note that given all options, only about 15% of people have Trump as their top choice. Kasich has the least support, with only 4%, so he is eliminated and his votes get redistributed in the next round.

Kasich’s support gets pretty evenly redistributed, though Clinton and Christie are the biggest beneficiaries, likely due to their relatively moderate positions. It’s not enough to change the state of the race though. Christie’s next on the chopping block

It’s a little hard to see since his support was so low, but the biggest beneficiary of Christie’s support is Sanders, followed by Clinton and Bush. Rubio’s the next to go, a little surprising given his position in the polls, particularly relative to Bush and Carson.

About two thirds of Rubio’s support goes to other Republican candidates, particularly Cruz and Carson. The remainder is taken mostly by Clinton. At this point, Clinton has gained the most support from where she started, up 3.6% points. In contrast, Trump has gained 1.9%; he’s not the “next best choice” for a lot of Kasich, Christie and Rubio supporters. Bush gets eliminated next.

Once again, Clinton is the biggest beneficiary with Trump and Sanders virtually tied for second. Clinton now has over 30% of the total vote. Carson is outta here.

Cruz and Trump win big with Carson gone, each gaining over 3 points while Clinton and Sanders don’t get half of that. With four candidates left and each of the parties with two candidates, Clinton and Sanders are still leading but Trump has closed the gap. Let’s see what happens when Cruz is given the boot.

Not surprisingly, Trump is the big winner of the Cruz departure (insert cruise joke here). Trump jumps ahead of Sanders, having added 18% points from his position in Round 1, more than the 15% he started with. By contrast, Clinton has gained 12% and Sanders 11% from where they started, showing the non-Trump Republicans are about evenly split between the Democratic candidates.

Sanders is next to go. Think about how a three-way race between Clinton, Trump and Sanders would have ended under our current system… Clinton and Sanders bitterly split Democratic support and Trump wins with perhaps 40% the popular vote. Both Clinton and Sanders are accused of being “spoilers”. Under RCV, both can be on the ballot at the same time, knowing that they’re likely to be the second choice for each others’ supporters.

Finally, a winner emerges. Clinton absorbs the vast majority of Sanders’ support and crushes Trump 59% to 41%, a popular vote margin not seen since Reagan-Mondale. While she was only the first choice for 24% of people, an additional 35% would rather see her win over Trump.

Conclusions

Again, while this approach is far from perfect, it is interesting to see how much effect our voting system could potentially have on our election outcomes. RCV allows for a broader, more diverse set of candidates to participate without running the risk of “spoiling” the outcome. It could also discourage negative campaigning, as candidates would be more concerned with being your second or third choice than in knocking their opponent down.

Voters in Maine recently passed a referendum to adopt RCV for many state and Congressional elections, after decades of living under governors elected with less than 50% of the vote. The state will serve as an excellent trial of RCV in the US, testing detractors’ objections that the system is too complicated for voters. If you’d like to help advance the cause of RCV, consider a donation to FairVote.org, a non-partisan charity dedicated to making democracy more representative.

For the sake of transparency, here’s the R code used to create this analysis.

*The Pew Research Center bears no responsibility for the analyses or interpretations of the data presented here.