The conclusion summarizes the book’s arguments concerning the influence of polarization and the fracturing of norms on the judicial process, and also its remedial suggestions.

How can groups best coordinate to solve problems? The answer touches on cultural innovation, including the trajectory of science, technology, and art. If everyone acts independently, different people will explore different solutions, but there is no way to leverage good solutions across the community. If everyone acts in consort, early successes can lead the group down dead ends and stifle exploration. The challenge is one of maintaining innovation but also communicating effective solutions once they are found. When solutions spaces are smooth – that is, easy – communication is good. But when solution spaces are rugged – that is, hard – the balance should tilt toward exploration. How can we best achieve this? One answer is to place people in social structures that reduce communication, but maintain connectivity. But there are other solutions that might work better. Algorithms, like simulated annealing, are designed to deal with such problems by adjusting collective focus over time, allowing systems to “cool off” slowly as they home in on solutions. Network science allows us to explore the performance of such solutions on smooth and rugged landscapes, and provides numerous avenues for innovation of its own.

This chapter uses data from the Dataset of Parties, Elections, and Ideology in Latin America (DPEILA) to understand the recent rightward move being seen in many party systems within the region, as well as the subsequent process of party-system polarization. The authors argue that major economic downturns favor radical, antisystem alternatives, thereby creating an opportunity for newly created parties to campaign on extreme policy platforms. They also demonstrate that polarization increases when leftist incumbents are associated with progressive policy change, as right-wing parties have become more ideologically extreme. This indicates that the left turn of the 2000s has at times favored the radicalization of important sectors of the right.

In the conclusion, we review the book’s chapters and argue that Latin America has experienced a resurgence of conservative forces in recent years. We analyze the supply and demand of a broad set of conservative alternatives, paying special attention to the processes of party-building, adaptation, and rebranding. We find that new right-wing forces often have weak organizations, but have been able to mobilize voters along noneconomic cleavages, including security, gender politics, and reproductive rights. The adoption of a highly conservative profile has allowed parties to access lower-class constituencies and mobilize mass support among them. The politicization of cultural issues, such as LGBT rights and religious identities, has contributed to polarization and the rise of populist radical right parties. These parties have flourished within the context of political and economic shocks and benefited from cultural backlashes and the crises of traditional right-wing parties. In these situations, politics becomes a zero-sum game and the stakes get higher. Democratic stability in the region is arguably at its most tenuous state since the age of military dictatorships. Interrupted presidencies have become realities in many countries over the past fifteen years, raising concerns about democratic stability and potential threats to democratic institutions.

This chapter analyzes the right in Venezuela under Chavismo. It argues that the main divide of Venezuelan politics is now between democracy and autocracy rather than the ideological left and right. As authoritarianism and repression have increased and Venezuela’s socioeconomic decline has worsened, right-wing movements and factions have prioritized competitiveness through a centrist approach over an emphasis on ideological purity.

This chapter addresses symmetry’s implications for gun rights and unenumerated fundamental liberties. Although recognizing an individual right to bear arms is inevitably asymmetric given current divides over gun regulation, the Supreme Court might moderate its decisions’ asymmetry in two ways: by allowing some meaningful room for firearms regulation, and by ensuring that the Second Amendment sometimes interferes with laws that are conventionally favored more by conservatives than by progressives. With respect to unenumerated rights, symmetry should support embracing some method for identifying such rights that avoids any predictable skew toward rights favored by one or the other major partisan or ideological camp. The Court’s current method of looking to “history and tradition” to define unenumerated rights could satisfy this standard, provided the Court applies it in a manner that allows recognition of new rights based on enactment of new laws over time in jurisdictions across the United States. In addition, the existing constitutional protection for parental rights, meaning parents’ authority to control key aspects of their children’s upbringing, appears not only defensible under the Court’s “history and tradition” approach but also symmetric given major current divides over certain parenting choices.

This chapter advocates an ethic of “symmetric interpretation” as a solution to the challenges outlined in Chapter 1. To prevent undue politicization of constitutional law, judges should favor, when possible, constitutional understandings that are “symmetric” in the sense of conferring valuable protections across both sides of the nation’s major political and ideological divides. By the same token, they should disfavor understandings that frame constitutional law as a matter of zero-sum competition between rival partisan visions. Favoring symmetric understandings in this sense will not always be possible. When it is possible, however, favoring symmetry may provide a point of common orientation for judges with differing policy preferences and interpretive outlooks. Reflecting this approach's inherent appeal, an inchoate preference for symmetry is already evident in judges’ opinions, oral argument questions, and reasoning.

This chapter refines the concept of constitutional symmetry and anticipates some potential objections. Contrary to what skeptics might assert, judges can reliably assess whether particular constitutional understandings are symmetric or not. In addition, favoring symmetry is valuable even though political alignments may shift in the future, and arguable asymmetries in the Constitution itself are not a reason to disfavor symmetric interpretations of provisions whose meaning is debatable. Symmetric interpretation also addresses contemporary challenges better than competing proposals to embrace “proportionality” in rights adjudication, give greater weight to existing precedent, or pursue one contemporary constitutional vision or another in no-holds-barred fashion. For judges who embrace an ethic of symmetric interpretation, a preference for symmetry should hold the greatest purchase in crafting general understandings of discrete constitutional provisions rather than overall interpretive theories or case-specific results, and judges should favor symmetric understandings even if their colleagues do not.

This chapter explores symmetry’s implications for equal protection jurisprudence. A stark political divide has emerged between two understandings of legal equality, particularly with respect to race: conservatives generally favor an “anti-classification” approach focused on ensuring government neutrality, while progressives typically favor an “anti-subordination” approach that allows affirmative governmental action to redress historical group disadvantages. Although the Supreme Court has increasingly aligned its jurisprudence with the anti-classification perspective, symmetry should encourage an approach that gives something to both sides. The Court might accomplish this goal in at least three ways: by returning to the focus on diversity reflected in its earlier decision in Regents of the University of California v. Bakke while giving this framework greater “bite”; by allowing majority groups to disadvantage themselves, so long as they are genuinely dominant at the relevant level of government; and by sometimes allowing selection of government criteria with a view to their demographic effects, so long as these criteria are themselves facially neutral.

This chapter addresses symmetry’s implications for separation of powers and federalism. It suggests that some major structural questions, such as the long-running debate over the president’s authority to fire or “remove” executive officers, hold an intensity out of step with their current political stakes. By contrast, other recent decisions, particularly those limiting agency authority over “major” policy questions and intensively reviewing the reasoned justification for certain policies, threaten to enable selective judicial disapproval of policies favored by progressives rather than conservatives. A preference for symmetry should support limiting or reconsidering these decisions. With respect to federalism, symmetry should likewise encourage the development of doctrines that grant parallel opportunities and protections to rival “red” and “blue” states dominated by either the Democratic or Republican Party.

This chapter outlines the challenges that current political polarization presents for constitutional law and judicial authority. Over the past fifty years, US politics have polarized, producing close political competition between two ideologically defined national parties that view each other with fear and distrust. This polarization has encouraged political actors in Congress and the federal executive branch to take legally aggressive positions and prioritize substantive policy achievements over adherence to good-governance norms or even constitutional restraints. At the same time, polarization has generated rival constitutional visions, and aligned slates of judges, that aim to advance partisan goals through constitutional interpretation. This environment poses risks for both judicial authority and constitutional law, because the public may lose trust in courts as neutral arbiters of constitutional disputes if it perceives them as wholly political institutions.

This chapter advances theoretical reasons to support symmetric interpretation. First, favoring symmetry accords with the Constitution’s character as a comparatively terse, “framework” document focused on establishing democratic procedures rather than definitive policies. Second, an ethic of symmetric interpretation accords with widely accepted features of judicial role-morality. Finally, symmetric interpretation accords with the framers’ own constitutional aspirations and interpretive methods. Multiple widely accepted theoretical considerations in constitutional law thus support preferring symmetric understandings when possible.

Originally established by “we the people,” as its preamble majestically states, the Constitution belongs to us all. But Americans increasingly treat it as the property of one political faction or the other. In keeping with their own preferences, conservatives interpret the Constitution to protect religion, limit gun control, and obstruct administrative governance while allowing state-level regulation of moral questions like abortion. Progressives see a mirror-image constitution that advances social justice, confers broad federal power, and allows flexible administrative regulation while at the same time limiting state and local police authority and guaranteeing sexual and reproductive autonomy. As national politics have grown ever more divided and polarized, preventing either side from implementing its goals through federal legislation, both coalitions have dreamed of capturing the courts and implementing their vision instead through constitutional interpretation. A document that should be a source of unity and shared commitments has become a vehicle for extending political conflict.

The book concludes by considering the broader implications of the findings of the previous chapters to the study of congressional primaries and the institution of Congress. This chapter advocates that we need to rethink how primaries matter in influencing candidate positioning and elite party identity. It also considers the implications for the scholarly community, citizens’ representation, and practical applications given the current focus on primary reform. It suggests several avenues for further research that can build on the book, as well as identifying potential limitations of this work. It concludes by considering the implications of these findings for the two parties in 2023 and beyond.

Having shown that primaries can reorient parties in Chapter 4, this chapter tests the first mechanism through which primaries are said to contribute to partisan polarization: the selective effect of voter preferences. It therefore tests whether primary voters prefer noncentrist candidates, all else being equal. Through a set of four analyses it tests whether primary voters prefer candidates further from the center when they are presented with a comparatively moderate and polarized alternative, whether moderate incumbents are more threatened, whether candidates who emerge from (ideological and factional) primaries are more “extreme” than other candidates, and whether there is any relationship between turnout and nominee position. Taken together, the findings in this chapter demonstrate the absence of a select effect from primary voters in nonincumbent primaries and only a weak and substantively small effect when an incumbent is present, suggesting that the polarizing effect identified in Chapter 4 is largely independent from the preferences expressed by primary voters.

The Introduction sets out the central puzzle that the book seeks to solve. Descriptively, it asks whether primaries have transformed in the twenty-first century by using a series of case studies to illustrate the central descriptive argument of change. It then frames the importance of the second half of the book, justifying the focus on elite partisan positioning and ideological change in relation to recent primary elections as a (potential) mechanism. It then clarifies the data collection process and sources used. Finally, it focuses on partisan differences between the Republican and Democratic parties before providing an outline of the book’s structure.