Why Hasn't the Top-Two Primary Been More Transformative?

Taken together, the studies described above suggest that primary reform is not a particularly promising leverage point. Primary type seems to make little difference on who votes, who runs, and who gets elected. And to the extent there is a moderating effect of primary type, the most consistent results suggest that more Republicans should be elected by closed primary.

Since most of the studies focus on the top-two primary, and the top-two primary is of the greatest current interest to reformers, let us focus here. Below are five possibilities that emerge from the studies.

Mechanically, the top-two primary’s greatest effect is going to come from districts that are so lopsided that they generate same-party general elections, thus electing candidates more moderate than would otherwise have been elected under the old system in which winning the Democratic or Republican primary was enough.

But, as Crosson’s analysis noted, “While reformers appear to have hoped same-party competition would occur at high rates in partisan-homogenous districts, the sorting analysis presented here suggests that political elites are able to avoid such competition.” Still, this is not fatal. It just suggests that more work needs to be done to induce more same-party competition: “Taken together, these findings suggest that political scientists’ claims that the top-two primary has had ‘no effect’ are premature and that the key to the system’s effectiveness lies in reformers’ ability to find ways to encourage more same-party competition.”

Still, same-party general elections do occur about one-sixth of the time, and such elections do tend to be less ideologically polarized.¹ Perhaps, however, this is not enough to generate enough of an effect, or at least not without greater incumbent turnover.

Another possibility is that parties, interest groups, donors, and even candidates coordinate behind the scenes to mitigate some of the potentially moderating effects because they do not like moderation. All of these groups have ways to shape candidate entry by steering resources (money and endorsements) toward favored candidates, deterring unwelcome challengers, and generally shaping voter perceptions through their networks.

In addition, even if more moderate challengers can win in an open election, things change when they are incumbents facing demands from donors and interest groups.² If the vast majorities of Democrats (or Republicans) in a legislature are more extreme, incumbents are going to face pressure from their colleagues to join the fight. In a polarized legislature, the middle is a lonely place to be. Most politicians are social animals, after all. This may explain particularly the continued polarization of the California State Legislature.

With multiple candidates running under the same partisan label, voters can no longer rely on partisan affiliation alone to choose their preferred candidate. In an idealized theory, this arrangement should force voters to evaluate candidates more independently. This has long been the theory of nonpartisan primaries—that absent partisan shortcuts, voters would look more closely at individual candidates and choose better candidates as a result. But in practice, most voters are too busy with the rest of their lives to evaluate individual candidates on the issues. They instead default to other shortcuts, such as endorsements, in-group affiliation, or most commonly, simply name recognition. And voters who do pay close attention often have strong and disparate preferences.

Name recognition is especially helpful for incumbents and for very well-funded candidates who can spend lots of money on advertising. Again, all decision rules empower some groups over others. If your theory of politics is that, all else equal, parties are more problematic than well-funded interest groups and private donors, and incumbents are preferable to challengers, then the top-two primary, or any nonpartisan primary, ought to increase the power of those two groups.

Also notable here is that California’s shift to nonpartisan top-two primaries generated an increase in about $18 million in contributions (compared to states that did not reform).³ And, to reiterate, when voters have to choose between multiple candidates running under the same party banner, money is that much more influential in helping them decide. A 2018 study by Steven Sparks underscores this point: "In the absence of differentiating party cues to guide vote choice, the information provided by campaign expenditures has a much larger effect for increasing challenger vote share and overcoming the advantages inherent to incumbency. Put simply, challengers in one-party contests are able to get a bigger bang for their buck, which better equips them to overcome the inherent advantage.”⁴ This is both because incumbents have a much bigger built-in advantage in same-party contests due to their name recognition, and because voters are much more likely to consider a challenger when they do not have to change their party.

Another possibility is that, even within the top-two contests, levels of cross-over voting are lower than expected. Remember, a key expectation of the top-two open primary is that Republican voters will vote for the more moderate Democrat if two Democrats compete in the general election, and vice versa. But this depends on orphaned Republicans bothering to vote in a general election in which the choice is between two Democrats. For many orphaned Republicans, a choice between two Democrats is a choice between two equally bad options; hence, better to abstain. It is the same for Democrats choosing between two Republicans. One study found that almost half of the orphaned voters abstained in a general election.⁵ Another found more than 40 percent abstention among orphaned voters, and concluded that voters of the opposing party had a hard time telling the difference between the ideology of opposite party candidates. (That is, Democrats had a hard time telling the difference between moderate and extreme Republicans, and vice versa; to most Democrats, a Republican is just a Republican, and vice versa.)⁶

These findings were again confirmed in a 2021 study, showing once again that orphaned voters abstain at high rates, leading the study’s authors to warn, “minority party voters and candidates may be disproportionately harmed by” the top-two primary system.⁷ A similar critique was leveled against the runoff elections in the South.

Another possibility is that voters have a hard time distinguishing moderate and more extreme candidates of the same party. One study conducted just before California’s 2012 primaries found that, “voters failed to distinguish moderate and extreme candidates. As a consequence, voters actually chose more ideologically distant candidates on the new ballot.” This led the authors to suggest that "lack of voter knowledge about candidate ideology and the problem of more than two candidates may be formidable obstacles” to electing more moderate candidates.⁸

Additionally, many so-called moderates in the voting population simply do not have strong preferences in either direction, not because they are inherently moderate, but because they do not pay enough attention to politics to have strong ideological views.⁹ Rather than selecting on policy, they pay attention to other factors, such as name recognition, looks, or other idiosyncratic character traits. Studies show that such voters actually de-emphasize policy and ideology. As a result, “moderate voters are less responsive to candidate positioning than non-moderate voters.”¹⁰

More broadly, there is considerable evidence that self-identified moderate voters do not necessarily hold moderate views on policy. Many moderates hold a mix of extreme views that do not neatly fit into either liberal or conservative camps, leaving them with moderate as the only reasonable label. Or, extreme liberal and conservative views on different issues average out to make a voter look moderate in a one-dimensional measure of ideology.¹¹ Similarly, though there may be many registered independents, those independents are not necessarily moderate either.¹² As Samara Klar and Yanna Krupnikov write in their book Independent Politics, most political independents vote like partisans.¹³

Many self-identified independents and moderates are more politically extreme than partisans.¹⁴ They are also less likely to reward compromise than registered partisans, contrary to conventional wisdom.¹⁵

In short, if the problem is the voters demanding extreme positions and rejecting compromises, the problem is not limited to registered partisans who vote in a partisan primary. Many independents and moderates are even worse. Notably, Republican primary voters who registered as independents were significantly more likely to support Trump than registered Republican voters in the 2016 primary, and Democratic voters who registered as independents were significantly more likely to support Sen. Bernie Sanders (I-Vt.) than registered Democrats. And according to regression models from an article by Joshua J. Dyck, Shanna Pearson-Merkowitz, and Michael Coates, the effect of registering as an independent was three times greater than a voter’s ideology in predicting support for Trump or Sanders.¹⁶

No matter what the primary rules, the deeper problem in our era of highly polarized conflictual politics is that a limited number of highly engaged partisans are driving political conflict. Many Americans are largely turned off from politics. It is not the opportunity to participate in primary elections that is keeping them from voting but the broader tenor of political conflict and media coverage of that conflict that keeps many voters largely on the sidelines. Independents are often more extreme and less compromise oriented than registered partisans, and largely distinguished by their frustration with and anger toward the political system. They are also often the least likely to support compromise, making them most receptive to the most anti-system populist candidates.¹⁷