Conclusions

This report set out to answer two main questions:

1. Are primary elections important contributors to hyper-partisan polarization?
2. Can changing the rules of the primary incentivize more compromise-oriented and moderate lawmaking, and if so, which rule changes?

Are primary elections important contributors to hyper-partisan polarization? The main conclusion here is that primary elections do appear to exert a polarizing tug on our politics. This tug is difficult to quantify because we cannot run the experiment in which American politics did not adopt primary elections in the early twentieth century, thus setting our electoral system along a different path entirely. However, the counterfactual does invite useful speculation. Given all the other forces that have driven polarization (the sorting of the parties, the consistently close national elections, the nationalization of politics), it seems unlikely on its face that a different path for nominating procedures would have pushed American political development down a different course.

There is ample evidence that fear of a primary challenge pulls candidates to reject compromise; to cultivate and stay close to their primary constituencies and the interests groups and donors who actively fund candidates in primaries; and to engage in partisan conflict to prove their bona fides with their primary constituencies. But findings on whether primary electorates are more ideologically extreme than general election electorates are somewhat mixed. The best answer is probably that primary electorates are a little more ideologically extreme than general election electorates, but whatever difference exists between primary and general election electorates is dwarfed by the difference between Democratic and Republican electorates. Indeed, the biggest divide, by far, is between the parties themselves. Contrary to popular theory, there is not some latent fifth column of sensible moderate voters, reluctantly waiting in the wings. The vast majority of voters have sorted into the two teams on offer.

Still, primary electorates are consistently distinguished by their high levels of political engagement. Regardless of ideology, they are stronger partisans.

Finally, partisanship and ideology are related but distinct concepts, and should be treated as such. We may need to revise our concerns about extremism to focus more on partisan conflict and compromise and less on policy preferences if we want to understand the dynamics of primary elections—and more broadly, the conflict consuming American politics right now.

Can changing the rules of the primary incentivize more compromise-oriented and moderate lawmaking, and if so, which rule changes? With this question, we are on firmer empirical ground in drawing conclusions, as primary type varies considerably across states, and several states have changed their primary type over the last few decades. The overwhelming conclusion across multiple studies is that the differences across primary types do not have much of an impact on who votes, who runs, or who wins. The most studied reform is the California top-two primary. Reformers had high hopes this reform would lead to more moderate politics, however its effect has been extremely muted. Of course, as with all reforms, it is quite possible that it could become more effective over time. But the record thus far is not encouraging.

The overwhelming conclusion across multiple studies is that the differences across primary types do not have much of an impact on who votes, who runs, or who wins.

The forces driving hyper-partisan polarization appear to be deeper than primary reform can reach. There are simply very few opportunities for would-be moderates to gain traction in this polarized climate, and few would-be moderate politicians have the desire to fight a losing battle within either of the two major parties. There is even less incentive to go it alone or form a third party, thanks to our single-winner plurality electoral system that channels all political opportunity to the two major parties. Thus far, the broader structural and national forces driving hyper-partisan polarization have proved much more important than variations in primary rules.

Of course, the studies discussed in this report have their limits. It is possible that scholars are using the wrong measures or measuring the wrong outcomes. It is also possible that the effects have been difficult to detect and take time to show up because political actors need to adapt. Above, I suggested some alternative ways we might study the effects of primary and primary reform. However, the more likely conclusion is that these studies are correct in their general assessment, and that broader structural forces driving hyper-partisanship are much more important than primary type or even existence.

There is still much to learn from the wide scholarship on primaries and primary reform. If you accept the conclusion that primary reform has a marginal impact, it is important to understand why, so that other reforms can benefit from the insights that studying primaries yields for how voters, candidates, and parties might behave under different sets of rules. Alternatively, if you accept the conclusion that primary reform has so far had a marginal impact, but could be an important lever of change going forward (especially since it appears to be relatively amenable to reform), it is equally important to understand why previous reform efforts have not succeeded in bending the river, so that future reformers can either avoid faulty assumptions that previous reforms made, or evaluate whether other baseline conditions that limited previous reform efforts may have changed such that future reform efforts are more likely to succeed. After all, our political system is in constant flux, and reforms that may have been irrelevant or unsuccessful under previous conditions may yet prove relevant and successful under different circumstances, as in a scientist who repeats an experiment under altered conditions. At the same time, we must heed Einstein’s advice that attempting the same thing over and over (under the same conditions) and expecting a different result is pure insanity.