Conventional wisdom says that as the number of Republican presidential candidates grows so does the possibility that Donald Trump wins the nomination again by virtue of a divided opposition. I’m not so sure. How often do a bunch of also-rans actually spoil the result? To put the question more precisely: How often would a candidate who can win an election with a plurality (not a majority) of the vote fail to win a head-to-head matchup with the second-place candidate?
We can answer that question with data collected by municipalities that use ranked-choice voting (RCV). As the name implies, RCV allows voters to rank their preferred candidates rather than cast only one vote. In the event that no candidate receives a majority of first-place votes, the lowest-ranking candidate is eliminated, and that candidate’s supporters’ second-choice votes are distributed to the remaining candidates. The elimination process continues until one candidate obtains a majority.
So, what do the results of RCV elections tell us about plurality winners who cannot win a head-to-head matchup with the runner-up? They’re rare.
According to the website Fair Vote, in RCV elections in which no candidate had a majority after the first round, the first-round leader ended up winning 88 percent of the time. In fact, even that figure overstates the role of spoilers. In the 12 percent of elections in which the plurality winner was not the eventual winner, most were either elections with obvious partisan imbalance — e.g., one Republican running against two Democrats — or elections in which the top two candidates were neck-and-neck. The scenario most feared by Trump opponents, in which a large majority of same-party voters would reject the plurality winner in a head-to-head matchup, appears to be extremely uncommon.
But what about 2016? Didn’t Trump leverage his celebrity to stand out just enough in a crowded field to overcome the GOP’s anti-Trump majority? Popular as this hypothesis may be, the evidence for it is thin. For example, Trump’s 35 percent in New Hampshire sounds unimpressive, but his nearest opponent, John Kasich, received just 16 percent of the vote. In order to defeat Trump in a hypothetical head-to-head matchup, voters for all of the other candidates — Cruz, Bush, Rubio, Christie, and so on — would have had to split about 70–30 for Kasich over Trump. That’s not impossible, but the RCV data teach us that voters (especially same-party voters) rarely divide so strongly with their second choices.
Results in South Carolina and Nevada followed the New Hampshire pattern in 2016. Later in the pivotal four-way race in Florida, which ended with Rubio’s withdrawal, Trump garnered 46 percent of the vote — a total so close to 50 percent that he surely would have won a head-to-head matchup against anyone there. Trump went on to win outright majorities in most of the Northeast, including New York. Cruz made a highly publicized last stand in Indiana, but Trump ended up winning a majority there as well, with Kasich a distant third. If Trump won the 2016 nomination mainly because of a crowded field, one is left to wonder exactly which candidate could have defeated him nationally head-to-head: Rubio, Cruz, Kasich? None of them seem likely.
All that said, it’s not out of the question that a crowded 2024 primary could hand Trump the nomination. He is such an unusual political figure that he is perhaps one of the few that could make it happen. Still, the prospect is unlikely. My advice to both Trump supporters and opponents is to not fret so much about the number of candidates. If in 2024 the GOP has a strong anti-Trump majority — which it did not have in 2016 — a singular alternative will probably emerge. Let the process play itself out.