Abstract
Partisan identity increasingly structures how Americans interpret the operation of democratic institutions, including the routine procedures meant to function impartially. This study examines how partisan identity shapes public evaluations of one such procedure, gubernatorial appointments to state supreme courts during competitive election years. Using a survey experiment in which respondents evaluated a hypothetical appointment under varied partisan conditions, we find that co-partisans express substantially greater support for the appointment procedure, while out-party respondents are more likely to oppose it. These effects appear regardless of respondents’ affect toward either party, suggesting that partisan identity, rather than sentiment, drives evaluations of this democratic process. Our findings indicate that support for these procedures is often conditional on partisan alignment, raising concerns about the durability of shared democratic norms.
Introduction and Research Question
Political conflict over judicial appointments has become a defining feature of contemporary democratic stress. The Senate’s refusal to consider Merrick Garland’s nomination in 2016, followed by the rapid confirmation of Amy Coney Barrett in 2020, highlighted how political elites increasingly use institutional procedures as partisan instruments (Segers 2020; Silverstein 2020). These events, emblematic of what scholars call “constitutional hardball,” exploit the letter of legal rules while violating informal democratic “guardrails” that sustain mutual toleration and procedural fairness (Fishkin and Pozen 2018; Levitsky and Ziblatt 2019). Such behavior challenges the informal “rules of the game” that underpin democratic legitimacy and are essential for sustaining public belief in institutional fairness even amid political conflict (McClosky 1964). 1
While federal confirmations draw national attention, similar dynamics are increasingly evident in state judicial politics. Partisan fights over state supreme courts have intensified, through controversial rulings, strategic appointments, and high-dollar campaigns. The Alabama Supreme Court’s 2024 ruling declaring that “unborn children” are legal persons triggered national backlash and revealed sharp partisan divisions in public knowledge and response (Chandler 2024; Ipsos 2024; Saric 2024).
In North Carolina, procedural challenges were used to invalidate ballots after a court election loss (Millhiser 2025), while Wisconsin’s 2025 state supreme court race shattered spending records, drawing nearly $20 million from outside PACs and prompting national figures to frame the contest as decisive for the survival of American democracy itself (Fortinsky 2025). Such episodes reveal how partisan actors increasingly view courts not as neutral institutions but instead as instruments of partisan political power.
Whether citizens uphold these norms consistently, or instead evaluate institutional actions through partisan identity, remains an open debate that has offered mixed evidence. Some research suggests that citizens tolerate or even endorse norm violations when they benefit their own party. Graham and Svolik (2020), for instance, find that many Americans are willing to trade off core democratic principles for partisan advantage. Armaly (2021) similarly demonstrates that evaluations of judicial institutions become increasingly contingent on group loyalty. In contrast, other scholars argue that partisan affect may not meaningfully erode democratic commitments. Broockman et al. (2023), for example, report little evidence that affective polarization reduces support for democratic rules. This mixed evidence underscores the need for studies identifying the specific institutional contexts in which partisanship does, and does not, shape citizens’ willingness to uphold core democratic procedures.
Judicial selection presents a critical test of this logic. Courts depend on public acceptance of procedural fairness and neutrality, yet their increasing politicization threatens that foundation (B. L. Bartels and Kramon 2022a; Gibson and Nelson 2014; Zilis 2018). This is especially true at the state level, where partisan pressures shape not only judicial rulings but also the institutional rules governing judicial selections. Governors have sought to expand appointment power (Kritzer 2019), legislatures have adjusted timelines based on partisan control (Melusky and Brazelton 2022), and research shows that even the procedural format, such as appointment versus election, matters less than how the process is framed (Armaly and Enders 2022a; Bonica and Sen 2017). As a result, gubernatorial appointments during election years, particularly in high-stakes, competitive contexts, may be increasingly perceived as political events with long-term consequences for partisan control. Given the above trends, we propose the following central research question: • How does partisan social identity, and particularly co-partisan status, influence public support for gubernatorial appointments of state supreme court justices during competitive election years and under conditions of heightened partisan conflict?
This question animates our research design and connects literature on democratic stability and social identity theory. The former emphasizes that democracies endure when citizens uphold institutional norms regardless of the political outcomes (Przeworski 1991; Weingast 1997), while the latter suggests that partisanship functions as a core identity that structures perceptions of institutional fairness and legitimacy. In polarized environments, where group attachments dominate evaluations, we expect citizens to selectively apply or relax support for the procedural “rules of the game” (McClosky 1964) based on whether their political group is advantaged. In such cases, institutional procedures are not evaluated on their merits but through a lens of group threat and partisan loyalty.
To test these expectations, we conducted a survey experiment in which respondents were randomly assigned to read a vignette about a governor appointing a state supreme court justice shortly before a competitive election. The governor’s partisanship was experimentally manipulated, allowing us to assess whether support for the appointment varied as a function of partisan congruence. This design isolates the effect of shared party identity in shaping evaluations of a procedurally valid, but politically salient, institutional act. It also allows us to test whether affective polarization further moderates these evaluations, or whether partisan identity alone is the dominant mechanism driving support. Understanding whether citizens uphold institutional procedures impartially, or only when they align with partisan advantage, offers insight into the resilience of democratic norms in an era of polarization.
We test three hypotheses: that individuals will be more supportive of co-partisan appointments (H1), less supportive of out-partisan appointments (H2), and that out-party support will decrease as affective polarization increases (H3). The results provide significant support for H1 and H2, but no evidence of moderation in H3. This pattern indicates that partisan identity, independent of affective intensity, conditions support for judicial appointment procedures. These findings provide additional support to the argument that adherence to the democratic “rules of the game” is increasingly outcome, and party, dependent. The next section develops the theoretical foundations for these hypotheses.
Partisanship, Democratic Norms, and Judicial Selection
Democratic systems rely on more than formal rules; they depend on shared expectations that political actors will exercise restraint, mutual toleration, acceptance of legitimate opposition, respect for institutional procedures, or what McClosky (1964) called the “rules of the game.” These informal democratic guardrails enable institutions to function predictably, even amid competition when outcomes are unfavorable (Dahl 2006; Lipset 1994; Przeworski 1991; Weingast 1997). Yet in an era of deep partisan polarization, scholars question whether citizens continue to uphold such norms impartially. A growing body of work suggests that many Americans endorse or excuse democratic norm violations when those actions benefit their own party (Armaly 2021; Graham and Svolik 2020). Others argue that core commitments to democratic procedures remain stable and are not easily swayed by partisanship (Broockman et al. 2023). These contrasting perspectives underscore a central tension: are democratic norms treated as universal principles, or as conditional rules applied selectively through the lens of group advantage?
Political science and social psychology alike show that partisan identity is a powerful form of social identity (Huddy 2001; Huddy and Bankert 2017; Mason 2018b; Tajfel 1978). Individuals do not merely hold policy preferences; they define themselves as part of political groups, and this group membership is how they interpret information, evaluate institutions, and respond to political cues (L. M. Bartels 2000, 2002; Goggin and Theodoridis 2018; Taber and Lodge 2006). As a result, partisanship influences everything from vote choice to economic perceptions (Prior et al. 2015), receptivity to misinformation (Miller et al. 2016; Nyhan and Reifler 2010), and even memory recall (Hennessey et al. 2021). As partisan identity becomes more central to individuals’ social identity, loyalty to one’s political group may supersede broader commitments to democratic procedures, particularly when institutional outcomes are perceived to advantage or threaten that group.
These dynamics contribute to what scholars term affective polarization: the tendency for individuals to view out-party members with hostility and in-party members with warmth and trust (Iyengar et al. 2019; Iyengar and Westwood 2015). As partisans sort more cleanly along ideological and social lines (M. Levendusky 2010), this emotional divide has deepened. Americans increasingly misperceive the other party’s values (M. Levendusky and Malhotra 2016), avoid crosscutting information (Roccas and Brewer 2002), and report social discomfort with out-partisans in personal and professional contexts (Gift and Gift 2015; Hersh and Goldenberg 2016). These antagonisms shape how citizens interpret institutional behavior: political acts undertaken by out-party elites may be perceived not as neutral governance, but as partisan aggression. In such contexts, even procedurally valid actions, like appointing a judge in a competitive election year, may be interpreted as illegitimate if they are associated with an opposing political group.
The current climate of polarization alters how citizens respond to political elites. Decades of research show that individuals rely on partisan cues from elected officials when evaluating political decisions (Nicholson 2012). But in a polarized environment, these cues do more than signal policy preferences, they activate group-based threat perceptions. When an out-party governor makes a high-profile institutional decision, such as a judicial appointment, citizens may interpret that action not as neutral governance but as an attempt to secure partisan advantage at the expense of their own group (Brewer 2007; Jardina 2014). This perception is often amplified by elite framing, as political actors routinely portray such decisions in partisan terms to mobilize supporters and de-legitimize opponents (Kingzette et al. 2021).
This dynamic underscores a broader concern raised by classic theories of democratic stability, which posit that institutions remain “self-enforcing” only when the public expects violations to be punished at the ballot box (Dahl 2006; Lipset 1994; Przeworski 1991; Weingast 1997). In a polarized political environment, however, this expectation weakens. When partisans view institutional behavior through a lens of in-group versus out-group advantage, they may excuse or even reward violations by their co-partisans. As Graham and Svolik (2020) caution, this can erode the electoral accountability that sustains democratic norms. These dynamics are not unique to the United States. Comparative research shows that deep partisan or identity-based cleavages often facilitate norm erosion and democratic backsliding across varied institutional contexts (Chiopris et al. 2025; Haggard and Kaufman 2021; Waldner and Lust 2018). Recent work also demonstrates that affective polarization can erode democratic commitments even in weak-party systems, as priming an “us versus them” logic reduces individuals’ support for democracy itself (Cox et al., 2025).
Yet the extent to which affective polarization undermines democratic norms remains an open question. Some scholars argue that elite framing and institutional context play a crucial mediating role. For example, Broockman et al. (2023) find that experimentally manipulating affective polarization produces little change in citizens’ democratic attitudes, suggesting that norm adherence may be more robust, or at least more conditional, than previously assumed. This unsettled empirical record highlights the importance of examining specific institutional arenas, such as judicial selection, where the stakes of partisan control are both symbolically and substantively clear.
The judiciary occupies a particularly revealing domain for this purpose. Unlike overtly political institutions, courts are traditionally insulated from partisanship and derive their legitimacy from public perceptions of neutrality, fairness, and adherence to procedural norms (Gibson and Nelson 2014). Yet growing polarization has made courts, especially at the state level, sites of visible partisan struggle. Research shows that when courts issue decisions favoring out-partisan groups, citizens’ diffuse support erodes (Armaly 2021; Zilis 2018). These patterns mirror broader findings that courts are increasingly evaluated through partisan lenses, with legitimacy contingent on whether judicial outcomes align with group interests (B. L. Bartels and Kramon 2022a; M. Levendusky et al. 2024). State courts, where most legal disputes are resolved and public interactions with the judiciary occur, are especially vulnerable, as their selection processes are more directly shaped by partisan actors and strategic institutional design (Wenzel et al. 2003).
Because courts are supposed to stand above politics, partisan behavior in their selection or evaluation offers a uniquely visible marker of democratic norm erosion. Prior research demonstrates that courts at all levels have become increasingly politicized, with judicial decisions, appointments, and judges themselves serving as means through which political actors pursue partisan objectives (Kelly 2016). Although formally procedural, judicial appointments are especially salient institutional acts because they visibly link courts to elected officials and partisan authority, particularly during politically charged moments (Armaly and Enders 2022b; B. L. Bartels and Kramon 2022b). As a result, ostensibly apolitical procedures, such as gubernatorial appointments, can become sites of partisan conflict and symbolic assertions of group dominance and loss. When citizens apply different standards to these procedures depending on the partisan identity of the actor involved, it reveals the extent to which democratic principles are treated not as universal rules, but as conditional norms tied to political advantage.
This politicization is especially evident in state supreme courts. Their composition reflects a combination of highly partisan appointment procedures (Barwick and Dawkins 2020; Kritzer 2019; Melusky and Brazelton 2022) and increasingly politicized judicial campaigns (Gibson 2008, 2009). Moreover, interim gubernatorial appointments are the dominant mechanism for filling state supreme court vacancies, employed in the vast majority of states (Brennan Center for Justice 2024). Recent scholarship suggests that the legitimacy of these appointments depends less on the formal mechanism, election versus appointment, and more on how the process is framed and perceived by the public. As Bonica and Sen (2017) argue, “the decision to elect or appoint judges is far less consequential than the rules that govern the two approaches” (587). Similarly, Armaly and Enders (2022a) find that “vacancies, alone, did not seem to influence views of the [Supreme] Court; vacancies, when politicized, do” (30). In other words, it is not the act of filling a seat that signals a norm violation, but whether that act is interpreted as a partisan power grab.
These insights underscore a core premise of our argument: the partisan framing and strategic use of judicial appointments, particularly during competitive election years, can erode public commitment to democratic norms. Even in the absence of explicit information about a court’s ideological direction or future rulings, respondents may interpret a governor’s decision through a partisan lens. Gubernatorial appointments made during competitive election years are not simply bureaucratic procedures; these are visible assertions of power by political elites. For partisans, these decisions carry deep symbolic and realistic weight: a co-partisan governor’s appointment may signal in-group dominance and security, while an out-partisan governor’s choice may be perceived as a direct threat to group interests. In such moments, even ostensibly neutral institutional processes become identity-relevant events, prompting partisan-based reactions. These dynamics provide the foundation for our experimental test: whether partisan identity conditions public support for gubernatorial appointments of state supreme court justices, even when those actions follow formal rules.
Hypotheses
Partisan polarization has increasingly shaped public opinion not only toward judicial decisions but also toward the institutional procedures that structure them. While the U.S. Supreme Court has drawn national scrutiny, particularly after the strategic blocking of Merrick Garland’s nomination and the confirmation of Amy Coney Barrett, state courts of last resort have become equally politicized battlegrounds. This tendency reflects not merely a passive bias but an emerging pattern of selective norm enforcement, where institutional behavior is judged primarily by its implications for partisan advantage. In today’s polarized context, what was once background noise has become the dominant mode of evaluation, particularly when institutional control appears contested or up for grabs.
Partisan identity, when activated in such high-stakes settings, transforms institutional procedures into perceived group threats or victories. Gubernatorial appointments to state courts, especially those made shortly before elections, are no longer perceived as routine exercises of executive authority. Instead, they are interpreted as power plays with direct consequences for partisan control. In these moments, citizens shift from evaluating whether a procedure is procedurally valid to whether it benefits their in-group. The result is conditional support for democratic norms, procedures like judicial appointments are endorsed or rejected based not on fairness or legality, but on whether they advance or undermine group interests.
We argue that this dynamic reflects a deeper pattern of democratic norm erosion. Partisan polarization (Iyengar et al. 2019; Mason 2018b; Tajfel 1978), reinforced by elite cues and strategic institutional framing (Armaly and Lane 2023; B. L. Bartels and Kramon 2022a; Nicholson 2012), has shifted public judgment away from consistent democratic standards and toward identity based evaluations. Perceived group threats, such as an out-party governor filling a judicial seat in a competitive election year, activate reactions that erode shared procedural commitments. As a result, adherence to the “rules of the game” (McClosky 1964) becomes conditional on which party stands to gain. This conditionality signals a broader risk of democratic backsliding: when citizens excuse institutional manipulation by their own party, they remove the public accountability that underpins democratic self-enforcement (Haggard and Kaufman 2021; Levitsky and Ziblatt 2019; Przeworski 1991).
This leads us to the following hypotheses. First, gubernatorial appointments serve as visible signals of partisan power, especially during moments of electoral uncertainty. When a co-partisan governor makes an appointment, partisans are likely to view the action as justified and legitimate, reinforcing group status and security.
Individuals will express greater support for judicial appointments made by a governor from their own party than for those made by an out-party governor.
In contrast, when an out-party governor makes the same appointment, the action may be perceived as a threat, an attempt to entrench partisan control or subvert democratic balance. These identity-based reactions can reduce support, even for procedurally valid behavior.
Individuals will express lower support for judicial appointments made by an out-party governor relative to a co-partisan governor.
The strength of these partisan effects is likely to vary depending on individuals’ affect towards their own party and the out-party. Those with higher levels of negative affect towards the opposing party are especially prone to view out-party appointments as less legitimate and more threatening. As a result, support for appointments by out-party governor should be decrease for respondents with greater negative sentiment towards the out-party.
Individuals with higher levels of negative affect toward the opposing party will be less likely to support judicial appointments made by an out-party governor.
Research Design and Data
To detect individuals’ propensity to support democratic norms relative to in-group or out-group affiliation, we found a survey experiment most appropriate. Using a survey experiment allows us to isolate a specific effect by largely mitigating potential bias that results from external influences, or spurious relationships from omitted variable bias (Mutz 2011, 9). We are further assured that our methodology is well-insulated from confounding factors due to achieving balance across our control and treatment groups (see supplemental material). Because we control what information changes between the randomly assigned participants, survey experiments in social science are highly regarded in their ability to conduct causal inference (Barabas and Jerit 2010; Mullinix et al. 2015; Mutz 2011). More practically, a survey experiment allows us to conduct our treatment over a representative sample of the population we wish to understand. Survey experiments also consistently replicate real-world phenomena (Barabas and Jerit 2010, 239); a feature that more complex model assumptions would negate. 2
We create three vignettes and, with the help of Qualtrics software, randomly assign respondents to one of the three. Our treatment is the party affiliation (e.g., Democrat, Republican, not shown) of the governor in a nearby state and their competitor in the upcoming election (always opposite parties). Respondents are given the preface that the governor is tasked, in a competitive election year, with appointing a state supreme court justice to replace a sitting justice who recently passed away (shown in Figure 1). We chose gubernatorial appointments since 45 states use gubernatorial appointments for interim appointments of state supreme court justices (Brennan Center for Justice 2024). After reading the vignette, respondents are prompted to answer “Yes” or “No” (randomized order) on whether they think it is appropriate for the governor to appoint this new justice in the given context. Out of all 980 respondents, 32.8 percent received the control, 33.2 percent received the “Democrat treatment”, and 33.8 percent received the “GOP (Republican) treatment”. Depending on one’s partisan affiliation (Democrat, Republican, Independent), as well as which treatment or lack thereof they received, we create a variable that dictates if the respondent was observing their vignette from the perspective of one of the three relationships, “out-party,” “in-party,” or “neither.” The first (out-party) applies to those who observe a vignette containing a governor of the opposite political party, whereas the second (in-party) dictates the governor was of the same party. The “neither” category captures all individuals in the control group. We choose to include independents to clarify differences between partisan groups, who are now compared to a third group, rather than each other. Additionally, there is evidence that independents do not view political issues through the same affective screen that the polarization literature identifies in partisan individuals, rather they potentially take a more cognitive (not affective) approach (Burden and Klofstad 2005). Control vignette shown to respondents.
Data for this paper was gathered in April of 2024 using the internet-based survey entity Lucid. Panel participants were selected to mimic national demographics, meaning the sample is nonrandom but still useful for extrapolation to the general public. The survey consisted of 61 questions, not including demographics as these were known from the panel selection. Along with demographic questions and our experimental vignettes, we concentrate on four questions asking individuals their opinion on either political party. Two of these questions are feeling thermometers, and two ask participants to rate their trust of Republicans and Democrats separately. The demographic questions that the theory tells us are most important to our design include party affiliation, education level, sex, political affect, trust, and race. 3 To create the variable for party affiliation, individuals identifying as independents are asked if they lean towards either party. If yes, we group the respondent into that partisan category. This tactic is consistent with the literature on independents’ political ideals; typically, independent ‘leaners’ are not considered independents at all. Instead, their political views map to one of two parties (Petrocik 2009).
Demographic variables were accounted for in the Lucid panel selection. In avoidance of listing out the many response options in each question, the question wording and response choices are shown in the supplemental material. Upon the survey’s completion, we had collected a total of 1,187 responses, 980 of which contain complete data. The demographics of our sample mirror national breakdowns except in terms of party affiliation, where our measure significantly decreases the number of independents. Out of 980 respondents, 38.5 percent were Republicans, 44.4 percent were Democrats, and 17 percent were “true independents” (i.e., did not indicate any lean). For gender, our sample contained 49.1 percent identifying as males and 50.8 percent identifying as females. 4 Slightly less than 94 percent of respondents had at least a high school diploma, and almost 50 (46.8) percent hold a college degree.
To record education, respondents were asked to document their highest level of schooling. After filtering non-responses, the education variable becomes a nine-point scale ranging from “1-Some high school or less” to “8-Doctorate degree.” For race, respondent’s in our panel were asked to indicate their identified race on a quite granular 15 point scale (after filtering non-responses). During pre-processing, we group the “Asian” categories into a single group. The same is done with Pacific Islanders. White respondents are used as the reference group when including race as a factor variable. The initial race question does not include an option for Hispanic as this is asked in a separate question block. Here, we create a dummy variable that puts all affirmative responses into level “1” with non-Hispanic respondents as the reference level. Lastly, the response options for household income are on a scale of 1–24 after excluding non-response options. 5 This scale begins at “Less than $14,999” and ends with “$250,000 and above.” Between the first value and $100,000 each category increases by $4,999. From $100,000 to $200,000 increments increase to $24,999. The second-to-last category captures the range from $200,000 to $249,999.
All respondents were asked the following question to record political affect: “On a scale from 0 (coldest) to 100 (warmest), how do you feel about the following? - Democrats,” and “On a scale from 0 (coldest) to 100 (warmest), how do you feel about the following? - Republicans.” The average rating for Democrats comes to approximately 50.7. Republicans receive a slightly lower rating of 45.9. 6 Through taking the difference between a respondent’s thermometer rating of their in-party and that of their out-party, we calculate the single variable “Affect” as a measure of affective polarization. All respondents were also asked about their trust towards each party with the following questions: “On a scale of 0–10, where 0 is not trusting at all and 10 is very trusting, how much do you trust... -Democrats” and, “On a scale of 0–10, where 0 is not trusting at all and 10 is very trusting, how much do you trust... -Republicans.” Here, on average, Democrats received a score of five while Republicans were given 4.4.
Methods
Because our dependent variable follows a binomial distribution, indicating if the respondent answered no (0) to supporting the governor’s appointment or yes (1), logit regression is most appropriate. Independent variables of interest include party, group, trust, feelings, and female. These variables are chosen with regard to our aforementioned theory and after testing multiple model specifications. Both increasing levels of affective polarization (Iyengar et al. 2012) and stronger ties between political-social identities (Huddy 2001; Mason 2018a) lead us to believe that the majority of the variation in the respondents’ answers is explained by their group status and partisan identification. This is further supported by West and Iyengar (2022), where it is found that when evaluating a situation that imposes a political loss or victory for an individual’s party, the effect of partisanship can supersede the influences provided by other demographic/identity characteristics. The frame of our vignette in the context of a state supreme court is in accordance with this existing research showing the politicization of judicial decisions, appointments, and judges at all levels of the judiciary. From the Supreme Court to state courts, courts have been a means of achieving political objectives (Kelly 2016)—the appointment process is especially important in politically salient moments as it visibly connects judges to the motivations of political actors (Armaly and Enders 2022b; B. L. Bartels and Kramon 2022b).
State supreme courts are themselves composed of a conglomerate of highly partisan non-interim appointment proceedings (Barwick and Dawkins 2020; Kritzer 2019) and candidate campaigns (Gibson 2008, 2009), making them ideal to test for political seepage into judicial matters. We justify further contextualizing our vignettes around an interim gubernatorial appointment because a majority of states (45) implement them (Brennan Center for Justice 2024), and they are separate from any campaign in which the judicial candidate may signal their policy preferences more intricately than is expressed by their association with a political party (i.e., the party of the appointing governor). This latter fact intends to force respondents in our experiment to reason only based on the group identifier, the governor’s party, yielding an isolated effect from their in-group (out-group) status on their decision to support the appointment. After testing multiple models, we find evidence supporting the findings of West and Iyengar (2022) in which partisanship as a group identity is found to explain a significant part, but not all, of the changes in group-based bias within political decisions. Demographic predictors regarded as important for political opinion (i.e., education, race, age...) had no effect on model results or performance; except in the case of gender, where our results reflect the potential contemporary salience of judicial appointments for female respondents. 7
Results
Models and results
Note. Standard errors in parentheses. Dependent variable is Propensity to Answer “Yes.”
∗p < .1; ∗∗p < .05; ∗∗∗p < .01.
In comparison to the parsimonious model one, models two and three show marginal improvements in explanatory power after the addition of affect, gender, and the gender-party interaction. Moreover, models two and three in Table 1 best encapsulate the theoretical underpinnings of our study. The addition of gender and affect depicts a significant negative relationship for both variables. 9 Regardless of the significance of the affect variable in these models, its contribution appears minimal given the coefficient value of 0.04, which translates to a 0.122 percent decrease in likelihood of appointment support. Practically speaking, an individual would need to experience a shift of 50 units in affect for the variable to decrease their likelihood of appointment support by a mere five percent.
In contrast, gender shows not only significance, but a substantively meaningful negative impact on the likelihood of supporting appointment. Model 3’s interaction between gender and partisan identification lets us see who is driving the negative effect from gender between Republican and Democratic women. We see that Republican women are the sole drivers of gender’s negative effect as the addition of the interaction takes significance away from the gender term alone. Hypothesizing precisely why Republican women are far less likely than their male counterparts to support the appointment is outside the realm of this study, and would require a more nuanced understanding of literature on gender and political decision-making. For now, we can only say that this result motivates future investigation.
Model 4 of Table 1 includes measures of respondent trust for either political party. Results show that only the “Trust Republicans” measure has any significant impact on appointment support, although this impact is (similar to affect) substantively minimal. We include measures of trust on the theoretical basis that they capture a similar, but different concept than affect. Questions on trust and feelings thermometers can be used to compute affect measures (Druckman et al. 2020; M. Levendusky and Malhotra 2016), yet as discussed in Druckman et al. (2020), either means of quantifying affect only captures general attitudes about broad objects (i.e., parties). These general attitudes may very well overlap at points, but utilizing either will result in idiosyncratic findings on how affect influences an outcome (Druckman et al. 2020; Iyengar et al. 2012; M. S. Levendusky 2009). In tandem with statistical tests to affirm each measure’s independence (see supplemental material), we can conclude that including both measures is justified. Overall, the lack of impact for the trust variable, and the minuscule contribution of affect to predicting appointment support provides evidence that the dynamics of in-group dominance or out-group animosity influence decisions that are made in a prominent political context, perhaps even more than the particular feelings (i.e., political affect) a respondent holds toward the political parties. It is an important point to differentiate between.
Marginal effects table
Note. Marginal Effects converted to percentage-based values.
A respondent’s status as Republican also produces a large effect. Compared to independents, Republican respondents show a 19.9 percent increase in the probability they affirm the appointment. Democrats also show a large positive effect when compared to independents, although slightly smaller than that of Republicans at 14.1 percent. An equality of coefficients test displays that the observed difference between Democrats and Republicans is statistically significant (p < .1) in all models besides model four in Table 1. 10 These results from Table 2 further inform those in Table 1 by depicting the magnitude of change group dynamics bring to an individual’s decision to support the appointment of a judge in this politically salient context. Finding more than a 10 percent swing in either direction is evidence of how important social group perception is to Americans in determining their support for government actions.
We show the predicted probability for supporting the judicial appointment within the group status in Figure 2. The plot also considers the partisan affiliation, allowing us to compare the rate of support of appointments between both parties within and across particular group statuses. The categorization of independents as in-group or out-group is practically meaningless as they do not belong to either partisan group, but their inclusion provides a baseline to compare partisans. As we expect, both Democrats and Republicans are least likely to support the hypothetical appointment when they are a member of the out-group. Our model predicts out-group Democrats support the appointment at a rate of 44 percent, whereas out-group republicans support at a slightly higher 51 percent. On the other end of Figure 2, our model shows that in-group Democrats and republicans were far more likely to support appointment with respective rates of 73 percent and 78 percent. The “Neither” category predicts appointment support for respondents identifying as republicans, Democrats or independents in the control group. Here, values for republicans and Democrats appear slightly above their out-group values, but overlap between the confidence intervals indicates that the difference is nonsignificant. The large positive effect of in-group status does lead to significantly higher values than any party affiliation in the neither category. Predicted effects of in/out group status on supporting appointment according to political identification.
Figure 2 displays clear differences between groups by partisan affiliation; however, intragroup comparisons appear non-substantial. Within any particular group, Republicans and Democrats do not show significantly different probabilities of support. This contrast from the variation between groups is notable and perhaps provides evidence on the strength of group identification relative to typical indicators of political decision making, such as partisanship (Iyengar et al. 2012; Mason 2018a; Theodoridis 2017). Though the intragroup variation is not statistically significant, we still observe higher predicted probabilities for republicans in each group. With our knowledge of the significant effects in Table 1, Republican respondents appear marginally more friendly to supporting the appointment in our hypothetical case; these results may identify an effect from the political memory of Amy Coney Barrett’s fast-tracked nomination (preceded by Merrick Garland’s blocked nomination), of which the republicans were the main beneficiaries (M. Levendusky et al. 2024; Segers 2020). Also notable is that Democrats experience a similar effect from group status, although they decried the process around Justice Barrett’s nomination and would ostensibly not wish to replicate such precedent. The main takeaway from Figure 2 is the magnitude of effect from group status. Democrats and Republicans strongly favor the judicial appointment when they can identify the governor as a member of their social group. This supports the conclusions of previous studies showing the influence of group identification on political opinion (M. Levendusky and Malhotra 2016; Martherus et al. 2021), and those that conclude that innate knowledge of shared or conflictual group identity may overrule broader political considerations (Mason 2018c; Theodoridis 2017).
Discussion and Conclusion
Our findings provide compelling evidence that partisan identity strongly influences public evaluations of gubernatorial appointments of state supreme court justices in a competitive political context. Despite the traditional insulation from politics the courts are ostensibly afforded, respondents were significantly more likely to support a judicial appointment when it was a co-partisan governor and significantly more likely to oppose when the appointing governor was an out-partisan. We can reject the null hypotheses for both H1 and H2. However, contrary to our expectations in H3, these patterns held regardless of party affect or trust scores. This suggests that party identification supersedes affective sentiment and is one of the primary drivers behind evaluations of procedural legitimacy in politically salient contexts.
This work extends and reinforces extant research on the social identity foundations of partisanship and affective polarization (Iyengar Sood, et al. 2012; Mason 2018b; Tajfel 1978; Theodoridis 2017). Importantly, these results demonstrate that partisan loyalty influences the legitimacy of democratic procedures that themselves reinforce the legitimacy of judicial institutions. In other words, the “rules of the game” appear increasingly contingent on which “team” is winning (Armaly and Lane 2023; McClosky 1964). The willingness to uphold democratic norms such as judicial appointments appear to rest on whether one’s group is advantaged by the outcome, reinforcing the notion that the public views justices more as political actors and less as neutral arbitrators of the law (Sinozich 2016).
The absence of moderating effects from party affect measures (feelings thermometer and trust) is particularly interesting. It may suggest that partisanship in the context of judicial appointments is a zero-sum game, emphasizing further influence of partisanship on evaluations of the judicial branch. Notably, our results revealed a consistent and significant gender effect. Female respondents were less supportive of appointments, which may reflect political memory of recent judicial controversies surrounding reported rights, such as the nomination and confirmation of Justice Barrett and the subsequent overturning of Roe v. Wade (M. Levendusky et al. 2024; Segers 2020). These findings invite other questions about how gendered experiences and recent political events shape trust in judicial procedures, particularly among women.
Taken together, this study adds to the growing body of evidence suggesting that politicization of the judiciary, at both the state and federal levels, has eroded perceptions of impartiality and legitimacy. As political elites increasingly frame judicial vacancies as a partisan zero-sum contest, polarized mass public respond accordingly. Not only does this threaten to further increase partisan polarization, but it continues to erode shared norms regarding what constitutes fair democratic practice.
Limitations and Future Directions
While this study sheds light on how partisan identity conditions support for routine democratic procedures, it is not without limitations. First, our experiment relies on hypothetical scenarios, which, though internally valid, may not fully capture the emotional salience or complexity of real-world judicial controversies. Respondents may reason differently when faced with actual appointments that involve real candidates, media framing, or specific policy implications. Second, we did not manipulate or directly measure perceived institutional stakes, such as whether the court’s ideological balance would shift, which may play a crucial role in heightening partisan responses. Future research could incorporate this dimension to assess whether perceptions of institutional consequence intensify norm conditionality.
Another puzzling implication of our findings regards the results showing Republicans as more likely to support the judicial appointment regardless of the partisanship of the governor. Based on the contemporary norm-violating behavior of the Republican party, we would not expect the present result showing Republicans’ general acceptance of the appointment, including from an out-party (Foa and Mounk 2025). Likewise, with the knowledge their party has not shown a propensity to follow norms or judicial decisions, potentially Republicans care very little about who is appointing justices and when. We theorize that our results could indicate a Republican willingness to communicate adherence to democratic norms with no intention to follow them once it impedes their interests. As is such, perhaps Republicans do not care who is appointed. If Republicans believe that any resulting judicial decisions from an out-partisan appointment will be countered by the overtly conservative Supreme Court of the United States, or by action from the executive and legislative branches, then there is little need to care for who conducts the appointment. We are unable to definitively state this in the present study. Future research should attempt to determine if the effect from partisan ques on Republicans changes when they believe their party will refuse to abide by any resulting decision that adversely impacts party interests.
Additionally, while we focus on party identity and affect, we do not explore other potentially salient identities, such as religion, or ideology, that may intersect with partisan evaluations of judicial procedures. Nor do we fully examine elite cues, media framing, or legal knowledge, all of which likely mediate how individuals interpret institutional actions. Understanding whether institutional trust varies by political knowledge or elite communication may offer greater insight into the mechanisms behind norm erosion.
Finally, while our findings document significant gender effects, we did not include direct measures of gendered attitudes or issue salience, such as reproductive rights, that might explain the gap. Future studies could explore whether recent high-profile decisions, such as Dobbs, have uniquely shifted women’s trust in judicial procedures, or whether this reflects broader concerns about institutional fairness and representation.
Overall, our study contributes to the growing literature on democratic backsliding by showing that even procedurally valid actions, such as a governor’s appointment of a judge, are filtered through the lens of group interest and partisan identity. Exploring how this dynamic unfolds in other democratic institutions, such as legislatures, election administration, or executive actions, represents a fruitful avenue for future research on the resilience of democratic norms in an era of polarization.
Supplemental Material
Supplemental Material—From Politics to the Bench: Partisan Determinants of Support for Gubernatorial Judicial Appointments
Supplemental Material for From Politics to the Bench: Partisan Determinants of Support for Gubernatorial Judicial Appointments by Aiden Parker and Jesse Usher Barrett in International Political Research Quarterly
Footnotes
Acknowledgments
We thank Professors Douglas Rice and Paul Collins for being close advisors throughout the course of this project. We also thank Professor Alexander Theodoridis for including our experiment on their survey. Finally, we thank the panelists at the 2025 New England Political Science Association who provided excellent recommendations and guidance.
Ethical Considerations
The Institutional Review Board of the University of Massachusetts, Amherst waived the need for ethics approval and patient consent for the collection, analysis, and publication of the data within this study. The approval/protocol number is 6,970.
Consent to Participate
Respondents provided a signature acknowledging participation in this study at the beginning of the survey.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
Replication data will be made available on author websites and on Dataverse.
Supplemental Material
Supplemental material for this article is available online. Supplemental materials include all alternative model specifications and the corresponding code. These will also be made available on author websites and Dataverse.
Notes
References
Supplementary Material
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