A voting system is supposed to allow voters to choose their elected officials, not choose for them. But which election system is used can actually have a significant impact on who gets elected and who doesn’t. The plurality voting system currently used in most U.S. elections is subject to what’s known as “vote splitting” and the “spoiler effect”. This phenomenon has had unfortunate consequences for candidates and voters in a number of specific elections, and it also means that in U.S. elections in general third-party candidates are at a disadvantage. Ranked Choice Voting (RCV) on the other hand empowers multiple candidates to run even if they overlap on some issues, because they can get high rankings from the same voters without worrying about splitting the vote.
Vote splitting occurs when there are multiple candidates who appeal to the same group. Imagine an election with three candidates A, B, and C. 40% of the population favors Candidate A and doesn’t like B or C at all. While 35% likes B the most but would also be ok with Candidate C, and they hate A. And the final 25% want C to win, but also likes Candidate B some, and strongly dislikes candidate A. Essentially the A faction has 40% support while the B or C group has 60% support. If the election is done using plurality, A will win because B and C have split the vote. To put it another way, C spoiled the election for B by not getting enough votes to win but pulling in enough so that B couldn’t win either. A’s win won’t be a reflection of what the majority of the voters wanted, but this is how the current system works.
If RCV is used in this same hypothetical election, A’s supporters will rank A #1 and leave their lower ranks blank, B’s supporters will rank B #1 and C#2, and vice versa for C’s supporters. The win will then go to B, which will reflect what the majority of the electorate wanted given the options available. This is an oversimplified example but it illustrates how RCV weighs all of a voter’s preferences and gives results that reflect people’s multifaceted political likes and dislikes, whereas plurality only counts who is each voter’s favorite. It’s also important to understand that RCV isn’t totally immune to the spoiler effect. A less popular candidate can still take enough high rankings from a more popular candidate to ruin their chances, but it is far less prevalent using this type of system.
When the spoiler effect happens in reality, sometimes a spoiler candidate only needs to pull a small number of voters in order to throw the election to their mutual opponent. One of the most notable examples of this in recent history is how the Green party candidate Ralph Nader impacted the 2000 presidential election. That year in Florida after the last recount, Nader had 97,488 votes, Al Gore got 2,912,253 and George Bush got 2,912,790. Gore would have won Florida if just a few hundred Nader voters had voted for him, and since Gore’s ideology was much closer to Nader’s than Bush’s was to either of them, Gore would have been the logical second choice for Green party supporters. Florida’s 25 electoral votes were enough to decide the presidency, so Nader voters actually went a long way towards helping Bush gain the presidency.
A lot of voters are now keenly aware of this problem and it puts third party candidates at a big disadvantage. People worry that if they vote for the Green Party candidate that they really want to win, they are subtracting a vote from the Democratic candidate that they would be ok with, which is essentially helping the Republican candidate that they don’t want at all. And the same goes for Libertarians running in the same race as Republicans, or Independents who may be aligned with one of the major parties on certain issues.
In a plurality system, this creates a vicious cycle where voters shy away from supporting third party candidates, which further weakens third parties in the U.S. Using RCV this would not be a problem, because voters could rank a Libertarian #1 and a Republican #2, or vice versa. RCV lets people support their ideal candidate without harming their second choice.
The problem of vote splitting of course isn’t exclusive to third party candidates. It can also happen with different factions within one party. It’s worth considering how plurality may have influenced the 2016 Republican Presidential Primary. There were about ten candidates with similar platforms, and then there was Donald Trump. The supporters of the non-Trump candidates combined with the “never Trump” voters whose main motivator was simply to avoid a Trump presidency, outnumbered the Trump voters in most places. But in order to leverage their non-Trump supporting majority, under the plurality system all of these voters would have had to unite behind a single candidate. They were never able to do that and thus Trump got the nomination in what appeared to be a landslide, because his opposition was so fractured between so many different candidates. If RCV were used in this primary instead there is a possibility that one of the other candidates would have gotten enough high rankings to win the nomination.
Whether it’s the Republican Primary, the Presidential Election, or a vote for school board members, the whole point of elections is to measure people’s preference and allow them to pick their elected officials. Plurality voting allows people to express one of their preferences in one way and because of that rigidity it’s a system that helps some candidates and some parties, and hurts others. Because RCV allows voters to more accurately reflect their preferences it can give voters more power to choose the candidate they really want, and help ensure that similar candidates and third parties get a fair chance.