The Supreme Outlier: How SCOTUS Stands Out Among Global Apex Courts

Literature Review: SCOTUS in a Global Context of Judicial Power and Partisanship

In recent decades, apex courts worldwide have emerged as central political actors. This shift in the balance of power—where judges increasingly serve as key decision-makers in areas traditionally reserved for legislatures or executives—was first widely recognized by Tate and Vallinder (1997) as part of “the global expansion of judicial power.” Decades later, Hirschl (Epstein et al. 2024, ch. 4) described this phenomenon as “one of the most significant developments in late-twentieth and early twenty-first-century government.”

However, while the power of apex courts has expanded globally, not all courts wield the same level of influence, nor do they exhibit the same degree of partisanship. I begin with a brief overview of the extensive American literature on the topic, focusing on SCOTUS, and then move on to the more limited cross-national comparative scholarship.

President Biden is not alone in his assertion that SCOTUS has become an extremely powerful and politicized institution. Legal scholars and political scientists agree that in recent years, SCOTUS has steadily accumulated power, often at the expense of other branches of government (for more, see Metzger, this volume). Lemley (2022) even dubbed SCOTUS the “imperial court,” asserting that it has systematically curtailed the power of Congress, the administrative state, the states, and lower federal courts, often using contradictory interpretative methodologies to aggrandize its power.

Brown and Epstein (2023) empirically tested the expansion of SCOTUS’s power and its disempowerment of executive authority. After analyzing 3,660 decisions from 1937 to 2021 (the first year of the Biden administration), they found that the current Roberts court is the most “antipresident” court in that period, ruling against the president more frequently, injecting itself more directly into policy matters, and displaying a strong preference for judicial supremacy over deference. SCOTUS’s decision in Loper Bright Enterprises v. Raimondo (2024), which overruled the 40-year-old Chevron deference doctrine, can be seen as the culmination of this strategy, clearly placing the court’s authority and judgment above those of experts in other branches (Metzger, this volume).

An apex court’s willingness to intervene in legislative or executive policies can signal a robust system of democratic checks and balances, with courts serving as bulwarks for democracy (Issacharoff 2015; Staton et al. 2022). However, Brown and Epstein (2023) challenge this conclusion in the case of SCOTUS: First, they demonstrate that Roberts justices show less willingness to check a president from the party that nominated them and are particularly inclined to limit the actions of a president from the opposing party. Second, they identify a recurring pattern in the Roberts court’s decisions—whether striking down or upholding presidential actions—where the court consistently seeks to expand its own power and influence across a broad spectrum of legal issues, more so than its predecessors. Consequently, they argue that SCOTUS perceives its primary role not merely as a defender of democracy, but as an enforcer of political agendas through its interpretation of the powers of the other branches. ¹

Unfortunately, although recent studies have examined the ideological or partisan motivations of judges in apex courts outside the U.S., as well as their tendencies to intervene in executive or legislative decisions, very few have leveraged insights from cross-national comparisons (Epstein et al. 2024; Garoupa et al. 2021). Furthermore, the few existing cross-national studies are often limited to studies of three to five courts with similar legal origins. Even so, based on the limited relevant literature I was able to find, one overarching conclusion stands out: SCOTUS is not only an exceptionally powerful apex court but also, by far, the most partisan.

Alarie and Green (2017, 248), for example, compare the decisions of individual judges in the high courts of the U.S., United Kingdom (UK), Canada, India, and Australia and conclude that “the U.S. Supreme Court appears to be an outlier in terms of both its politicization and level of disagreement. . . . On all our measures, the judges on the Court are the most overtly political—they are the most consistent across areas of law, form into disparate blocs, tend to vote consistently with the politics of who appointed them, and disagree with each other openly and often.”

Comparing justices’ votes to invalidate legislation in the apex courts of the U.S., Canada, and Australia, Weiden (2011) reaches similar conclusions, also noting that SCOTUS justices are more inclined to intervene in legislative matters. Weinshall et al. (2018) developed an empirical scale to measure the level of ideological decision-making in religious and political rights cases across the supreme courts of the U.S., Canada, Israel, India, and the Philippines. Their findings also show that U.S. justices exhibit the highest level of partisanship, significantly surpassing the other courts studied. As they put it, “The American court seems to be in a league of its own” (Weinshall et al. 2018, 343).

These studies, along with more qualitative comparative research (e.g., Garoupa and Ginsburg 2019), discuss various institutional factors that may influence a court’s political power or the extent to which judges follow their own political views when deciding cases. In this article, I systematically compare these factors across a broad array of 38 apex courts.

Methodological Framework for Comparing SCOTUS with Apex Courts

What historical, legal, political, cultural, and institutional factors shape the power and role of apex courts in democracies, and how do these factors apply to SCOTUS? How does SCOTUS compare to other apex courts in its ability to influence government policies, its level of engagement, and the motivations driving the decision-making of its justices? What explains any observed differences?

To explore these questions, I compare SCOTUS with apex courts in the 37 other OECD countries. Since the OECD countries are mostly developed, high-income nations with advanced economies and similar legal standards, they provide a suitable benchmark and an interesting range of cases for comparison. While a commitment to democracy is required for joining the OECD, some member countries have recently experienced democratic backsliding. In some cases, populist leaders have accused the apex courts of excessive judicial activism and of interfering in government policies to advance political agendas. Turkey, Poland, Hungary, and Mexico have taken significant steps aimed at curbing the powers of their apex courts, and similar measures are being considered in Israel.

Data for the comparisons were drawn primarily from the apex courts’ annual reports from 2022 to 2024 and were then manually coded by the author and supplemented with information from the Comparative Constitutions Project (Elkins and Ginsburg 2022) and the Organisation for Economic Co-operation and Development (OECD 2022). The data are available in the online appendix. The criteria for comparison consist of institutional factors identified in previous comparative studies as influencing justices’ levels of partisanship, activist judicial decision-making, and direct involvement in policymaking (Alarie and Green 2017; Garoupa et al. 2021; Weiden 2011; Weinshall et al. 2018).

Throughout the comparison, I distinguish between two ideal types of apex courts: constitutional courts (CCs), which primarily address constitutional issues, and supreme or high courts (SCs), which typically serve as the final appellate courts while also adjudicating constitutional matters (Garoupa et al. 2021; Stone Sweet 2012). ² CCs, sometimes referred to as “European-style” courts, are centralized bodies outside the regular judiciary. In contrast, SCOTUS is the archetype of the American-style, decentralized model of SCs. As discussed below, constitutional and supreme courts generally differ in their judicial review powers, methods of judicial selection, independence, and overall role. Comparing SCOTUS to all OECD apex courts, and specifically to similarly styled SCs, highlights its unique institutional design.

Historical and Institutional Development

Figure 1 illustrates the establishment of apex courts over time. Blue circles represent SCs, while red X marks denote CCs. The size of each marker indicates the number of courts established in the same year. The shaded gray areas highlight two significant historical periods for the diffusion of CCs: the post–World War II era and the third wave of democratization.

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Figure 1

Establishment of Apex Courts by Year and Type

The figure begins in 1789, marking the establishment of both SCOTUS and the Swedish SC. ³ SCOTUS is not only the oldest active apex court in the OECD, but it was also founded on the basis of the world’s oldest written constitution. Likewise, it was the first court to clearly establish judicial review and assert its power to invalidate laws that contradict the U.S. Constitution, beginning with the landmark case of Marbury v. Madison in 1803.

Figure 1 illustrates the relatively slow diffusion of SCs since the eighteenth century, compared to the rapid spread of CCs during the mid-to-late twentieth century. In response to the lessons learned from the Third Reich’s misuse of the rule of law and the judiciary’s complicity, several countries in continental Europe adopted new constitutions that established CCs with the authority to review and strike down legislation, as well as to adjudicate conflicts among governmental branches. Inspired by the American model, these post–World War II CCs adopted judicial review mechanisms as a key democratizing measure (Ferejohn and Pasquino 2004). The third wave of democratization further accelerated the diffusion of CCs to Latin American and post-communist countries (Bugarič and Ginsburg 2016). Following periods of authoritarian rule, CCs in these regions were explicitly designed to act as robust checks on political power, with exclusive jurisdiction over constitutional matters.

The differing historical evolution of SCs and CCs can help explain their distinct powers within political systems, as well as their underlying cultures, values, and norms. The historical context is relevant to all the criteria compared in this article. I begin by examining the impact of historical context on judicial review powers but return to its implications throughout the discussion on constitutional rights and institutional norms.

Judicial Review: Balancing Power Between National Political Branches and Supranational Court Oversight

Today, all OECD apex courts have significant judicial review powers to intervene in executive power, decide on highly salient and political cases, and interpret constitutional documents, either as the only specialized court (CC) or as the highest instance (SC). However, while all CCs uniformly possess explicit constitutional authority to invalidate legislation that conflicts with the constitution, SCs exhibit a more diverse range of constitutional review powers.

In OECD countries, about one-third of SCs (six of seventeen) have similar explicit authority as CCs, often incorporated through constitutional amendments made in the late twentieth century, inspired by the new wave of constitutionalism that established these courts. Another third of OECD SCs, however, have limited constitutional review powers. SCs in countries like the UK and New Zealand adhere to the principle of parliamentary sovereignty and cannot directly invalidate legislation. Instead, these courts employ mechanisms such as declarations of a law’s incompatibility with the constitution (without nullifying it) or of “nonapplication” of laws to specific cases. Finally, in the remaining five OECD SCs, including SCOTUS, the authority to invalidate laws remains unwritten and self-declared, granting these courts a unique degree of judicial power.

Self-declared constitutional review powers, such as those held by SCOTUS, can provide a court with greater flexibility compared to courts with constitutionally enshrined authority. Courts with explicit powers often face constraints, such as the requirement for a supermajority to invalidate legislation, which is built into the constitutional framework to prevent overreach. In contrast, self-declared powers rely heavily on the court’s own sense of restraint, which may vary depending on the broader political climate. When courts enjoy institutional legitimacy (see Gibson, this volume) and do not fear consequences from elected officials, there is less incentive for self-restraint. I return to this point below in my discussion of political context.

In recent decades, two significant dimensions have been added to the discussion on constitutional review powers: the rise of supranational orders and the role of constitutional amendments. Ginsburg and Versteeg (Epstein et al. 2024, ch. 3) suggest criteria of “finality” to classify judicial review powers according to the institution that has the final authority on constitutionality. They construct a spectrum ranging from systems where judicial review is not final to those where it is. At one end of the spectrum are countries with a tradition of parliamentary sovereignty, where the parliament holds the final authority. Next are national courts subject to supranational orders, such as the Mexican Supreme Court, whose decisions may be overturned by the Inter-American Court of Human Rights if they contradict the American Convention on Human Rights. Further along are systems where judicial review is final, but decisions can be overturned through constitutional amendments. At the furthest end are systems where apex courts can overturn constitutional amendments based on a constitutional eternity clause, which prohibits the amendment of particular provisions; constitutional custom (Korea); or doctrines of unconstitutional constitutional amendments (Colombia [Roznai 2017]).

I adopt these criteria with a few modifications. First, the parliament is considered to have the final word not only when courts lack the authority to disqualify legislation, but also when the parliament is granted legislative override power to validate laws even if the court has declared them unconstitutional (often with time limits or special majority requirements—e.g., Canada, Israel, and Finland). Second, I divide the spectrum into three measures, testing apex courts’ power of finality against that of (1) the parliament, (2) a supranational court, or (3) the constitutional authority. This is necessary because many apex courts can be classified in more than one category. For example, the German CC (like other European courts) is embedded in a broader European supranational order, but its constitution also has an eternity clause. Another example is the Israeli SC, which asserted its authority to invalidate constitutional amendments in 2024, yet still has a legislative override clause for some basic rights.

Figure 2 illustrates the distribution of 38 OECD courts across these three measures, represented in the three rows. Each column represents a national court, identified by the International Olympic Committee’s abbreviation of the country’s name; countries with SCs are marked in bold. Red rectangles indicate instances where the apex court holds final constitutional review power, while blue rectangles represent cases where the parliament, supranational court, or constitutional body has the final authority. White rectangles denote situations where the apex court’s authority to invalidate constitutional amendments is still uncertain—that is, where the constitution includes an eternity clause but does not explicitly grant the court the power to enforce it, and the court has yet to assert this authority.

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Figure 2

Finality of Constitutional Review in OECD Apex Courts

Figure 2 highlights SCOTUS—located in the second column—as a powerful court in terms of the finality criterion. While 76 percent of apex courts hold final authority in only one area, typically over parliamentary legislation, SCOTUS has final authority in two. Only one of the 38 courts, Korea’s, has final authority in all three areas.

The second row in Figure 2 shows that the vast majority of apex courts are subject to the rulings of a supranational court—nearly two-thirds of SCs and over 95 percent of CCs. SCOTUS, however, does not answer to any other legal authority. Indeed, the U.S. is one of only seven OECD countries in which the apex court’s power is unchecked by supranational entities. This is significant because even if instances where a supranational court overrides an apex court’s decisions are rare, and though domestic judges can sometimes resist the supranational legal order (Lustig and Weiler 2018), the supranational court’s potential authority serves as a deterrent to restrain the power of apex courts.

The absence of a supranational order may have broader implications for institutional values. Supranational courts, often established with a globalist vision in contrast to nationalist movements, tend to focus on protecting human rights (many even include “Human Rights” in their names). These courts are dedicated to safeguarding the core values of liberal democracies and are more likely to encourage national apex courts to protect liberal rights, even overruling them when they fail to do so. Supranational courts also provide national courts with legal tools and normative justifications to intervene in policies that threaten human rights, often with the implicit or explicit message that if national courts do not act, the supranational court will. I will expand on this in the next section.

The third measure of finality, represented in the last row of Figure 2, is less straightforward. SCOTUS is among the majority of apex courts that do not engage in constitutional amendments (66 percent of all OECD courts and 88 percent of SCs). However, due to the rigidity of the U.S. Constitution, SCOTUS is often viewed as having the final word on constitutional matters. As explained in the next paragraph, although judicial decisions can theoretically be overturned through constitutional amendments with a vast political federal and state majority, this is nearly impossible in today’s political landscape. Consequently, SCOTUS can be seen as holding greater finality in constitutional review, even compared to apex courts in countries where procedures for invalidating constitutional amendments—typically requiring a special process and a supermajority in the apex court—are explicitly outlined.

Constitutional Framing, Political Context, and Institutional Norms

As the world’s first written constitution, the U.S. Constitution has served as a model for constitutions worldwide. However, today it stands apart from other OECD national constitutions in several key respects—most notably in its longevity, brevity, textual stability, rigidity, and omission of social and socioeconomic rights (Law and Versteeg 2012). I will briefly examine these factors and explain how, together with the political context, they not only empower SCOTUS relative to the political power of other apex courts but also shape its core institutional norms in a distinct direction.

The average age of constitutions currently in effect in OECD countries is 69 years—166 years younger than the U.S. Constitution. Excluding three countries with no formal constitution, the median year of adoption is 1975, which is 186 years after the U.S. Constitution was adopted. What is even more remarkable is that relative to its age, the U.S. Constitution stands out for having very few amendments. It is difficult to make direct and exact comparisons with other OECD countries because there are salient differences in the magnitude and nature of constitutional changes, as well as in what counts as an amendment. Some countries have undergone hundreds of amendments—Mexico being an extreme example. However, the U.S. Constitution is clearly unique in this aspect. ⁴

The infrequency of amendments not only highlights the U.S. Constitution’s stability, but also reflects the significant difficulty of amending it, especially compared to other nations with less rigid systems. The challenge of constitutional amendment must be understood in light of the political context. In the increasingly polarized politics of recent decades, securing a two-thirds majority in both houses of Congress to propose an amendment, let alone a three-fourths majority of state legislatures or conventions to ratify it, has become nearly impossible.

Compared to other OECD constitutions, the U.S. Constitution is notably concise. As a rough indicator, it contains approximately 7,600 words (including the amendments), making it about 2.5 times shorter than the average length of other OECD constitutions (in English translations) and almost two times shorter than the median. Scholars note that due to the succinct nature of the U.S. Constitution and the difficulty of amending it, the U.S. constitutional order evolves primarily through SCOTUS’s judicial interpretation. ⁵ This process ultimately enhances the court’s power compared to apex courts in countries with more detailed or flexible constitutions (Ginsburg and Huq 2020).

Furthermore, compared to other OECD constitutions, the U.S. Constitution provides limited detail regarding the Supreme Court’s role. Article III establishes the judiciary and grants judges life tenure with good behavior, but beyond that, the Constitution offers minimal regulation. In contrast, many OECD constitutions contain more comprehensive provisions on the structure, powers, and jurisdiction of their highest courts, often including mechanisms for judicial review or constitutional oversight (as discussed in the previous section).

The limited mention of the Supreme Court in the U.S. Constitution does not automatically result in a strong court. It may just as likely lead to a weaker one, allowing the political branches to more easily curb its power. For example, when a constitution does not explicitly set the number of judges on the apex court (as is true for 13 OECD constitutions), it makes court-packing more feasible. However, given the political reality described previously, it is difficult to imagine even a regular majority consolidating to enact such changes. While in the past, the Constitution’s lack of detailed regulation on SCOTUS may have been used by political branches to deter it from obstructing their actions, today that same vagueness is more likely to be used by SCOTUS to expand its power.

Comparative studies suggest that when constitutional frameworks and political conditions enable the use of mechanisms to overturn judicial decisions or constrain judges, the latter are more likely to consider the potential consequences of rulings that conflict with the preferences of the regime or the public (Carrubba et al. 2008). In the U.S., the rigid constitutional framework, combined with a deeply divided public and often gridlocked political branches, makes it difficult for the government to effectively push back against SCOTUS’s decisions. This environment allows U.S. Supreme Court justices to more boldly disregard government and public opinion and prioritize their own policy preferences in comparison to judges in other OECD courts, as I discuss below.

Before I move to the next section, it is important to address one final aspect of U.S. constitutional exceptionalism: its omission of social, socioeconomic, and welfare rights (Chilton and Versteeg 2020; Law and Versteeg 2012). These rights, often referred to as positive rights, are now considered standard features of international human rights regimes and the constitutions of many European states (Ignatieff 2005). They are explicitly protected, to varying degrees, in 23 of the 35 OECD countries with written constitutions, particularly in newer constitutions. The right to education, for instance, is the most commonly included social right: The constitutions of Finland, Portugal, Spain, and Switzerland all guarantee a free, basic education (OECD 2022). And rights to welfare can also be guaranteed: The Constitution of Finland, for example, guarantees the “means necessary for a life of dignity” to those unable to obtain them otherwise and requires public authorities to “promote the right of everyone to housing and the opportunity to arrange their own housing” (ch. 2, § 19). These rights are often linked to liberal social values and provide courts with additional doctrinal tools to intervene in authoritarian policies.

While the presence of these rights in a constitution does not guarantee their enforcement (Chilton and Versteeg 2020), their inclusion, along with the historical context of the post–World War II and third-wave democratization periods, shapes the core institutional values of apex courts. Courts established during these eras were designed as antimajoritarian institutions with the explicit purpose of protecting human rights and liberal democratic values.

This is not to suggest that SCOTUS’s justices do not view themselves as defenders of rights; they certainly do. However, SCOTUS lacks the ethos, tools, and institutional incentives to counter threats to human rights that are central to newer constitutional courts, which were specifically designed to combat authoritarianism (Huq and Ginsburg 2018). Infamous SCOTUS rulings like Plessy v. Ferguson (1896) and Korematsu v. United States (1944) are often cited as moments when the court failed to protect fundamental rights (Keck 2024). Unlike many other apex courts and constitutions that underwent significant reform after similar such controversies, SCOTUS and the U.S. Constitution have largely retained their structure and ethos. In fact, Ginsburg and Huq (2020) argue that the exceptional design of the U.S. Constitution empowers SCOTUS to develop doctrines that can facilitate rights violations rather than prevent them.

Case Processing, Court Structures, and Collegiality

The comparison of the structure and operational case-processing features of OECD apex courts also highlights the unique characteristics of SCOTUS that contribute to its powerful and partisan nature. The analysis focuses on several key features, as illustrated in Figure 3: access to the apex court, agenda-setting powers, docket size, number of justices, panel structure and size, and the consensus norm. These elements are interrelated. I first discuss their combined effects in general terms and then examine their specific implications for SCOTUS. Figure 3 presents scales for each feature across the 38 OECD apex courts in the bottom bar and focuses on the 17 OECD SCs in the top bar. SCOTUS’s placement is indicated by the arrow.

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Figure 3

SCOTUS’s Position Among OECD Apex Courts on Scales of Institutional Features

Ginsburg and Versteeg (Epstein et al. 2024, ch. 3) position courts on a spectrum from most closed to most open and accessible. At one end are courts where only certain governmental and legislative institutions can bring claims (common in CCs). Next on the spectrum are courts where litigants can bring cases to the apex court through the ordinary court system. Finally, courts that allow citizens or even noncitizens to raise claims of rights violations, typically through constitutional petitions, provide the broadest access.

Courts are generally passive institutions in the sense that they cannot initiate claims but decide only on cases petitioned to the court. Thus, the more accessible a court is, the more opportunities and potential political power it may hold. However, this potential power is eroded if the court’s rules and procedures do not allow it to pick and choose the cases it wishes to engage with from the pool of petitions brought to its doors. If the court, for example, is swamped with constitutional petitions that it must address, its overall power is reduced.

High control over dockets strengthens a court’s power by allowing it to select specific cases and by enabling it to shape standing and justiciability doctrines. These doctrines can broaden judicial review, allowing the court to influence policymaking without necessarily invalidating laws or reviewing cases. The mere possibility of judicial intervention can deter policymakers from certain actions (Garoupa and Ginsburg 2019).

Agenda-setting capabilities, which enable justices to strategically select cases, factor into the court’s legitimacy, the potential outcomes, and the opportunity to advance desirable policy preferences. Indeed, comparative studies have shown that strong agenda-setting mechanisms are correlated with more partisan courts and politically driven (attitudinal) decision-making (Alarie and Green 2017; Weinshall et al. 2018). Justices’ ability to strategically select cases based on expected outcomes is enhanced when they know in advance the number and identity of their fellow panel members, as this allows them to anticipate their colleagues’ likely votes. This scenario occurs when deciding cases en banc or within a fixed chamber of permanent justices; by contrast, rotating panels introduce a measure of uncertainty. ⁶ A fixed panel’s size and composition also encourage panel effects, negotiations among justices, and long-term strategic decision-making.

Agenda-setting mechanisms are directly linked to the size of a court’s docket, which varies significantly among apex courts—from fewer than 100 cases annually to over 10,000, as shown in Figure 3. The size of a court’s docket, along with the number of judges on judicial panels, influences the overall judicial workload. These workloads determine the amount of resources that can be invested in each case and affect the cost of registering dissent (Epstein et al. 2013; Weinshall et al. 2018).

Low workloads are therefore associated with higher rates of dissent. The norm of consensus reported in Figure 3 refers to the proportion of resolved cases with at least one dissenting opinion. To maintain collegiality and authority, a minority of SCs and some CCs do not publish separate opinions, which is indicated as “100 percent N/A” in Figure 3. In other courts, the consensus norm ranges from approximately 40 percent to 99 percent, with more than 80 percent consensus in the vast majority of courts. These rates are influenced not only by workloads but also by ideological differences in preferred policies and the presence of underlying norms regarding the acceptability of dissent (Alarie and Green 2017; Garoupa and Santos-Botelho 2022; Kelemen 2018). Another relevant factor is panel size, with smaller and more cohesive panels tending to minimize dissent (Weinshall et al. 2018).

Figure 3 highlights SCOTUS’s position as an extreme case in several key characteristics. While it falls in the middle of the spectrum regarding accessibility, it has the highest agenda-setting powers, a notably small docket, the largest panel size—regularly sitting en banc—and the lowest consensus rate, with approximately 60 percent of cases featuring at least one dissenting opinion. As discussed, these features contribute to a powerful court where justices are often engaged in partisan decision-making.

Appointment Process and Tenure

The U.S. has one of the most politicized and partisan judicial appointment processes among OECD countries. While appointments to apex courts are inherently political, most OECD countries have implemented mechanisms to incorporate professional considerations and prevent governmental control over the judiciary. Figure 4 presents a Venn diagram illustrating the distinct use and overlap of three such mechanisms.

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Figure 4

Mechanisms to Ensure Professionalism and Independence in OECD Judicial Appointment Processes

Two of these mechanisms involve the participation of nonpolitical professional jurists in the selection process. The first mechanism, depicted in the red circle, involves the judiciary's direct participation in the appointment process; it applies to 20 OECD apex courts (10 SCs and 10 CCs). Participation may occur through the division of appointments among the three branches of government, allowing judges to unilaterally appoint a percentage of justices—usually a third, as seen in the Korean and Italian CCs. In other cases, judges are part of the appointing body, deliberating and voting on nominations alongside members of the political branches. Israel’s judicial appointments committee, which includes three justices, two government ministers, two members of parliament, and two public representatives, exemplifies this approach.

The second mechanism, adopted by 12 OECD countries (10 SCs and 2 CCs) and represented by the blue circle, involves the inclusion of jurist committees in the selection process. These committees are typically composed of top lawyers, legal scholars, and judges. They perform a range of roles in the selection process, from choosing nominees, as seen in the UK, to screening candidates, as in Iceland, or offering merit-based recommendations that may vary in their binding nature—either legally binding or followed as a matter of constitutional convention—as in Canada and Norway.

The third mechanism, requiring a special majority vote to appoint justices, is employed by 22 countries, primarily those with CCs (17 CCs and 5 SCs, depicted in the green circle). This mechanism is not intended to promote professionalism directly, but rather to prevent the government or a narrow legislative majority from taking over the court. It acts as a safeguard to ensure the independence of the judiciary, thereby increasing the likelihood that it will protect democracy from overreach by political branches. Supermajoritarian requirements also promote the selection of moderate and consensual justices who enjoy broad support. This approach reduces polarization around apex courts and, consequently, indirectly fosters professionalism.

It is important to note that the SCOTUS appointment process, which involves presidential nomination and Senate confirmation, can achieve similar outcomes during periods of divided government—when one party controls the presidency and the other controls the Senate. However, this scenario is not relevant under unified governments, which are more common, and it does not close the comparative gap with most OECD countries. In 21 of these countries, both political branches participate in the selection process. The remaining countries are typically parliamentary systems, where the involvement of both branches makes less sense as the government is accountable to the parliament and not separately elected.

Figure 4 covers 34 of the 38 OECD countries, with the majority having more than one mechanism in place to ensure professionalism and independence. The appointment process in only four countries lacks all three mechanisms. In one of these, Australia, professionalism is still ensured through the formal legal requirement to consult with the attorneys general of the states before making any appointments. Additionally, reforms are underway to incorporate such mechanisms in two others: Poland, aiming to restore judicial independence after the former populist administration, is in the final stages of amending its judicial appointments process, including introducing a requirement for a three-fifths majority in parliament to approve appointments; and in the Czech Republic, President Petr Pavel established a pilot advisory board in 2023, composed of six lawyers and law professors, to serve as a jurist committee. Assuming these reforms take effect, the U.S. may soon be the only OECD country where all actors involved in apex court appointments are politicians, and where a simple majority is sufficient to appoint justices. The only country that has a more overtly political appointment mechanism is Mexico, which introduced public elections for all judges, including Supreme Court justices, in a late 2024 judicial reform. However, one-third of the candidates are still nominated by the judiciary, with the remaining two-thirds nominated by the federal executive and legislature.

This was not always the case in the U.S. Until 2017, Senate rules required a supermajority to end debate on SCOTUS nominations. This meant that even when the president’s party controlled the Senate, presidents were inclined to choose moderate nominees who could gain support from at least a few senators from the minority party. However, the 2017 Senate rule change, which eliminated the filibuster for SCOTUS nominations, reduced the minority party’s influence, paving the way for more extreme nominations and contributing to a more polarized and partisan court (see Cameron and Kastellec, this volume).

A political court does not inherently contradict democratic values (Peretti 2001). In fact, CCs are often considered semipolitical institutions, sometimes even appointing retired politicians as justices, as seen in the French Constitutional Council. However, when nominees and justices become more extreme in their political views and base their decisions increasingly on partisanship, they may oppose perceived threats to democracy only when these threats come from a rival party, while supporting overreach when it comes from their own side. Since threats to democracy can arise from either end of the political spectrum, an extreme version of a partisan court can endanger democratic structures and values.

Furthermore, political courts are intended to reflect longer-term but prevailing public preferences. This is ensured by appointing justices to serve for a limited number of years. Indeed, in two-thirds of OECD CCs (14 CCs), justices are appointed for nonrenewable terms (to maintain independence) ranging from 8 to 15 years. The average is 10 years and the mode is 9. In 19 percent of OECD CCs (four courts), justices’ tenures are renewable for timeframes ranging from 2 to 10 years, and the rest (three CCs) have mandatory retirement ages of 65 to 75. A mandatory retirement age mechanism also promotes judicial turnover and ensures that justices’ perspectives remain aligned with the public and political branches. Eighty-two percent of OECD SCs (14 courts) enforce retirement between ages 65 and 75 (and two more have renewable terms). In some SCs, such as Japan’s, there is a deliberate strategy of appointing justices close to the mandatory retirement age to ensure a high degree of turnover, allowing the government to continuously adjust and correct the court’s ideological direction (Law 2016).

With its literal interpretation of “lifetime” appointments, SCOTUS is (once again) an outlier. Justices are increasingly appointed at younger ages and serve on the court for several decades, which contrasts with many principles underlying political appointments (see Cameron and Kastellec, this volume). Furthermore, SCOTUS is the only court where justices have complete control over the timing of their retirement, allowing them to significantly influence the partisanship of their successors—except in cases of unforeseen circumstances. This practice undermines a fundamental principle of political appointments, which is to reflect public preferences in the composition of the court. It also further strengthens the already powerful SCOTUS justices by enabling them to influence policy for longer periods than most politicians and public servants. They can plan long-term strategies to gradually and more effectively shift policy, and by strategically timing their retirement, they can extend their influence well beyond their tenure.

Conclusion

Comparing SCOTUS with other OECD apex courts reveals that it is an outlier in several key ways, many of which are rooted in its historical background and the age, succinctness, and rigidity of the U.S. Constitution. While there are profound benefits to such a stable constitutional framework, a polarized political environment—which effectively prevents any constitutional change or even the threat of change—creates a court that is, in many ways, unchecked by the political branches. Unlike many other apex courts, SCOTUS is not constrained by supranational courts; nor is it restricted by time demands, and unlike most other courts, it can pick and choose its docket. It has a more politicized and less professional appointment process than other apex courts, which, coupled with unique case-processing rules and exceptionally low consensus norms, fosters and reinforces partisan decision-making. SCOTUS’s highly powerful and deeply partisan nature enables it to act without public support or fear of consequences from elected officials, further solidifying its influential role in American politics. Ironically, these same elements also make the court more vulnerable to capture by political parties through the regular nomination process and susceptible to exploitation for advancing extreme political agendas, whether from the right or the left, depending on its composition.

In light of these distinctions, which features, if any, should be targeted for reform? While SCOTUS diverges from other apex courts in all the mentioned dimensions, one feature stands out as the most impactful: a lifelong judicial term. This aspect is misaligned with other characteristics of SCOTUS and is most at odds with the rules of other apex courts. Setting a term limit was indeed a central focus of President Biden’s proposed reforms. However, the specific proposal of an 18-year term deviates from the established norms in other apex courts and may represent a somewhat hybrid approach from a comparative perspective. ⁷

The proposal to reform judicial terms raises two comparative caveats. The first is the risk of selectively adopting institutional elements from different systems. Judicial and political systems are holistic, with interrelated features that influence each other in complex ways, making institutional design changes challenging. This interconnectedness complicates establishing a causal link between a specific change and its intended effect. Therefore, it is difficult to predict the impact of any given reform. The second concern stems from the experience of many countries that have undergone judicial overhaul processes aimed at curbing the power of apex courts over the past decade (though often in the very different context of democratic backsliding). Any court reform should be approached with immense caution; changes should be pursued with broad consensus and implemented prospectively.

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