The Washington PostDemocracy Dies in Darkness

Opinion How our system of primary elections could destroy democracy

In Pennsylvania, Republican Senate candidates Mehmet Oz, left, and David McCormick are currently separated by 0.1 percent of the vote. (Michelle Gustafson/Bloomberg News)

Self-government is supposed to make sense. That, after all, is the premise of Thomas Paine’s celebrated tract, “Common Sense.” Yet the way we are practicing self-government now, as demonstrated by this year’s primaries, is utterly irrational. It may cause the demise of democracy unless we figure out a way to fix it fast.

In state after state, winners have one-third of the votes or less. J.D. Vance won Ohio’s Republican Senate primary with 32.2 percent of the vote. Nebraska’s GOP gubernatorial primary was won with 33.8 percent. In Pennsylvania, the virtual tie between Mehmet Oz and David McCormick for the GOP Senate nomination means that about 31 percent will be enough for victory.

There is no way to say these winners are the collective choice of each primary’s voters. The fundamental idea of an election is that the will of the majority should prevail. To be sure, in our constitutional system, we guard against a tyranny of the majority through a set of checks and balances. Still, when we put questions of public policy and the representation of citizens to a vote, we want that vote to be decided by the larger share prevailing over the smaller — not the other way around.

Yet we undermine that objective when we let a candidate win an election with a mere plurality of votes. If the winner has only one-third of the votes, that means two-thirds — twice as many voters — were on the losing side. That’s backward.

And it doesn’t have to be this way. Seven statesrequire candidates to win a majority of primary votes and hold runoffs if they don’t. But holding another election isn’t even necessary if states would follow the lead of Maine, which holds an “instant runoff” by requiring ranked-choice voting in primaries.

I have argued before that Congress should require its members to be elected by majority vote, and this would be an improvement on the current process. But as a practical matter, in a two-party system, a plurality-winner rule generally isn’t a grave problem: When there are only two candidates, the one with more has a majority. In fact, using a plurality-winner rule in a general election tends to generate a two-party system. Known as Duverger’s law, the strategic incentive created by the need to win more votes than any other candidate prompts political factions to coalesce into two competing parties, each vying to capture the electorate’s median voter.

But Duverger’s law does not work in party primaries. Political science has not settled on why; one theory is that competition in primaries is not stable enough for strategic dynamics to exert sufficient force. Whatever the reason, it is evident that using the plurality-winner rule for party primaries does not yield two-candidate competitions. Instead, it delivers the kind of irrational outcomes we are witnessing this year, where a political party’s nomination goes to the candidate who lost two-thirds, or more, of the party’s votes.

The harm this irrationality causes is not confined to the party; it affects the public as a whole. Pennsylvania offers an illustration: If Oz ekes out a primary win with 31 percent of the vote, he might go on to win the general election. But doing so wouldn’t vindicate him as the most preferred candidate. November’s voters might have preferred McCormick even more. But they will never get a chance to express this preference, assuming McCormick is knocked out in a primary that fractures among multiple candidates with none receiving even a third of the total.

One might argue that McCormick should run in November as an independent. But Duverger’s law, operative in the general election, effectively nullifies that option. Only the two major-party candidates have any realistic chance of success.

The consequence is that the double use of the plurality-winner rule is a double whammy. First, in the primary, where Duverger’s law has no force, the plurality-winner rule fragments the field, preventing a majority of voters from choosing the candidate who truly is most preferred overall. Then, in the general election, when Duverger’s law takes hold, the plurality-winner rule prevents a candidate who lost a primary — even an irrational primary — from mounting a meaningful independent campaign.

The danger of this double whammy would not be so great were it not for the MAGA movement’s hostility toward democracy itself. Self-government can tolerate aberrational outcomes if the opportunity for self-correction in future elections is preserved. But when a political faction threatens to repudiate future elections upon attaining power, it is essential that the existing electoral system not award victories to this faction’s candidates who aren’t genuinely the majority’s choice.

Thus, add this to the list of electoral reforms having utmost urgency: eliminate plurality-winner primaries — which either state legislatures or Congress can do. Otherwise, we may lose our democracy not because we made that choice, but because an irrational and anti-majoritarian system produced that result.