As the 2024 presidential primary season approaches, we can anticipate a large number of Republican presidential hopefuls will declare their candidacy. This will be reminiscent of the 2016 primary season which began with 17 candidates. Meanwhile, should President Biden decide not to run for re-election -- perhaps even if he does! -- Democrats will also have a primary season beginning with several hopefuls, if not in 2024 then certainly in 2028. Neither party has a rational procedure for choosing the final winner in multiple candidate primary seasons.
If the current primary election rules apply, the 2024 primaries will be conducted as a series of state elections over many months, each decided by plurality rule, not majority rule. Instead, plurality rule in a series of primaries among a large number of contestants is highly likely to prevent majority rule as a matter of simple arithmetic; each individual primary in the sequence being essentially a plurality vote process of eliminating candidates. This effect is especially acute in the Republican primary system which awards delegates on a winner-take-all basis, permitting huge leads to develop very quickly, speeding the process of elimination.
In other words, a repeat of 2016 looms. During that Republican primary season, Donald Trump won early primaries with only 25 to 30% of the vote. Meanwhile, while the more traditional established vote was split among several more candidates including Jeb Bush, Chris Christie, Carly Fiorina, and John Kasich. Because Trump retains solid support among at least 30% of Republicans, he is primed to do that again in 2024.
The problem facing Republicans in 2016 serves as a rough numerical illustration of the problem in 2024. The party had a core constituency of roughly 60% of its members. These are Republicans who yearn for a return to the often-recited "principles:" free markets; individuality; personal responsibility; law and order, de-regulation, lower taxes, smaller government, and so on. Another 30% are fringe voters who grieve for an imagined past, and a candidate who will vaguely promise to shake things up, protect unregulated gun ownership, freedom from vaccine and mask mandates, and bans on accurate history taught in schools. "Undecided" made up the other 10%.
Now suppose that the 60% core voters are split among five candidates, averaging 12% apiece. With the core vote split among the several candidates, a fringe candidate with only 30% of the vote can defeat the other candidates and the 60% core voter policy preferences they represent.
The Essence of the Problem
The presidential primary season culminates in a convention to nominate the final winner as the candidate for the fall general election. The prize in each primary consists of delegates to the convention. But each primary influences the next one in the sequence; the winner gains not only that election victory, including the associated delegates, but also an advantage in the next election in the sequence, growing donor support, improvement in the polls, media reports on the candidate's momentum, and priceless television interview time.
One by one, contenders who lose in the early primaries drop out as their poll numbers fall and donors cut them loose. As the candidate pool shrinks, winners of contests later in the series will get larger vote percentages, perhaps even greater than 50%. But even 50+ margins should not be interpreted as a majority-rule result since they were made possible by the elimination of contenders in plurality-rule contests.
Toward Majority Rule: Ranked Choice Voting (aka Instant Runoff Voting)
Instant runoff voting (IRV) results in majority rule in each contest in the series, regardless of how many candidates enter those contests. IRV increases the likelihood that the winners of early primaries will represent the preferences of the majority of voters.
Here's how it works: instead of voting for just one candidate, the IRV ballot permits the voter to vote for several contestants, ranking them in their order of preference. After the polls close computers tally the first-choice votes. A winner is declared only if the top vote-getter has a majority of all votes cast. Otherwise, a new round of calculation ensues in which the last-place finisher is eliminated and the voters' lower-ranked votes are redistributed to their other candidates. If this second-round calculation produces a majority vote-getter, that candidate is the winner. If not, additional rounds are calculated until a candidate does get a majority.
Conventional runoffs are time-consuming, expensive, and inconvenient for the voters. Consequently, neither party uses them. The default has been to designate the plurality vote-getter as the winner and move on to the next primary contest. By contrast, IRV is conducted by computer and results can be established very quickly after the polls close.,
The current procedures for presidential primaries threaten a repeat of 2016, including the nomination of Donald Trump as the presidential candidate in the Republican party. To safeguard against such a biased process, the Republican Party should implement ranked choice voting.
Similarly, the next time the Democratic Party faces a presidential primary season -- whether in 2024 or 2028 – – it will no doubt attract a large number of hopefuls, and therefore face the same challenge of selecting the nominee by a majority-vote process; Democrats should implement rank choice voting. Moreover, if the Republicans use IRV they are likely to put up a more competitive candidate; the Democrats should use IRV as a defensive response.
 Instant runoff voting does not delay reporting election results. Delays are due to the collection of data from the individual precincts and regions of a state. Once the data is collected, the calculations employing that data are nearly instantaneous.
 Wisconsin's own Katherine Gehl provides an excellent description of how rank-choice voting works. https://www.youtube.com/watch?v=YvjfMTlefc8&t=23s
William L. Holahan is Emeritus Professor and former Chair of Economics at the University of Wisconsin-Milwaukee.