An Integrative Social Identity Model of Populist Leadership

In recent years, the questions of what populism is and how populist leaders mobilize their followers have been the subject of extensive debate. While the social psychology literature holds unique theoretical tools that can be used to explain leader-follower dynamics, these have not yet been applied to understand populism and populist leadership. In this paper, we aim to discuss populism as a social-psychological concept and provide a comprehensive approach to examine the interactions between populist leaders and followers by using the identity leadership model (see New Psychology of Leadership , Haslam et al., 2020). Accord-ingly, we propose an integrative model in which we suggest that populism should be treated as a social-psychological concept based on (i) strong ingroup identification; (ii) interactive leadership processes that open spaces to followers for enacting their ingroup identity that end up with mobilization against vertical (e.g., elites) and horizontal (e.g., minorities, refugees, opponents) outgroups; (iii) leader's ingroup prototypicality and identity entrepreneurship that is boosted by using shared grievances, narratives of collective victim-hood, and the destabilization of mainstream opponent leaders. Furthermore, by discussing real-world examples and recent studies, we aim to show how the content of what it means to be ‘us’ and what is seen as moral to ‘us’ can be shaped by populist leaders for mobilization.


| INTRODUCTION
The word populism has been used to ring the alarm bells for the better half of the century.The word's use over time has shown a sharp increase since the beginning of the 1960s, and it has reached new heights in the 2010s (see Figure 1).This is not without reason.Populism has a multifaceted and complex relationship with democracy; it can be a friend as well as a foe (Mudde & Rovira Kaltwasser, 2017).Nonetheless, the resurging modern form of populism that scholars have been ringing the bell about tends to come to life when there is an accumulation of grievances (Mudde & Rovira Kaltwasser, 2018).With populist leadership and mobilization, this accumulation of grievances turns into a yearning for social change while leaving the legitimacy of democratic institutions in question.Despite this negative connotation and a vast amount of research on populism, there is still a disconnection between social psychology and the other disciplines that study populism (Obradovic et al., 2020).This paper has three key aims: First is to review discussions around the definition of populism in order to then provide the building blocks of a theoretical bridge between the social identity approach in social psychology (Tajfel & Turner, 1979;Turner et al., 1987) and the approaches to studying populism (e.g., Barr, 2009;Jansen, 2011;Mudde & Rovira Kaltwasser, 2013, 2017;Norris & Inglehart, 2019;Ostiguy, 2017;Schulz et al., 2018).Second, to summarise the recent social-psychological studies employing the social identity approach to leadership (see Haslam et al., 2020, for an overview) while drawing real-life examples from various populist contexts, to illustrate the need to understand populist strategies in this explanatory framework.Third, following the recent literature, this review aims to identify the key paths to understand how populist leaders create situations in which they (counter)mobilize their supporters/ followers against the outgroups by using identity-framed populist communication strategies such as the "us" versus "them" distinction, relative deprivation and collective victimhood.To fulfil these aims, the current paper suggests an Integrative Social Identity Model for Populist Leadership (ISIMPL; see Figure 2) by utilizing various concepts and literature such as identity leadership, engaged followership, leader destabilization, collective victimhood, and populist attitudes.

| POPULISM AS A SOCIAL PSYCHOLOGICAL CONCEPT
Although one of the first attempts in the social sciences to map populism as a distinct phenomenon dates back to Shils (1956), there is still no consensus on "what populism is", especially as a psychological concept.One of the most important reasons for the absence of a universally recognized definition of populism probably lies in its contextual nature and pejorative use.Populism manifests itself differently depending on the contextual condition, and, thus, it is defined as a thin-centred ideology that needs a host ideology (Mudde, 2004(Mudde, , 2017;;Mudde & Rovira Kaltwasser, 2017;Stanley, 2008).The term thin-centred ideology refers to the ideologies that address only part of the political agenda or specific political questions, rather than covering all aspects of life.While thick-centred ideologies such as socialism, fascism, or liberalism provide information and offer transformation for the economic and political system, thin-centred ideologies like populism centre on ideas that do not have far-reaching implications for political life.
Debates on the concept of populism revolve around three main issues: definition, origin, and impact.We argue that focusing on the commonalities and intersections between the definitions of populism will help us to create a framework for the social psychology of populism.Mudde (2004Mudde ( , 2017) ) defines populism as an 'ideology' that systematically uses the distinction between the people and the elites.Weyland (2001), on the other hand, conceptualises populism as a strategy used by populist leaders to gain power through creating unestablished, unmediated, socio-cultural hierarchies in society, related to the people and social classes.To sum up, following all these definitions and recent discussions, we suggest that populism should be treated as a social-psychological term, based on: 1. a mutual-agentic and interactive relationship between a leader and followers with a shared common ingroup identity 2. leaders' identity prototypicality and entrepreneurship by routinely using shared grievances, deprivation, destabilization of outgroup leaders, and collective victimhood of the ingroup 3. strong ingroup identification and mobilization against outgroups as a consequence of mutual-agentic leader-follower interactions.

| SOCIAL IDENTITY APPROACH
The social identity approach in social psychology is based on a large body of research inspired by social identity theory and self-categorization theory (Tajfel & Turner, 1979;Turner et al., 1987).According to this approach, people have the capacity to identify not only in terms of their personal identity ('I') but also in terms of social identity ('we', 'us').This identification shifts the psychological understanding of the self and allows people to engage in collective behaviour.
Social identity is also related to the knowledge of belonging to a social category or a group, accompanied by an emotional significance and the attribution of value to people's group membership (Tajfel, 1978).Shared emotions, values, opinions, and experiences help to build a sense of belonging and strengthen people's perception of being a group member (Brewer, 2001;Hornsey, 2008;Reicher, 2004).In turn, group membership reinforces the prototypicality of an ingroup by creating a sense of 'we-ness', which is then also embedded in ingroup norms and values (Hogg, 2001;Reicher & Hopkins, 2001).
According to the social identity approach, group members strive to maintain positive self-esteem through their collective self-definition and by increasing intergroup differentiation (Jetten et al., 2001(Jetten et al., , 2004;;Jetten & Spears, 2003).In other words, the ingroup favours its members and assigns them superior status; hence, it draws a boundary between us and them, and a negative image distinguishes the ingroup from the outgroup who are perceived as threatening and evil (Branscombe & Ellemers, 1998;Tajfel & Turner, 1979).Here, it is important to remember Laclau's (2005) conceptualization of populism which refers to it as an antagonistic political logic that constructs the people and mobilizes them against the other, an enemy.The populist logic encourages the formation of antagonistic camps that hold a positive image in favour of the ingroup (Bos et al., 2020;Laclau, 2005;Mudde, 2004;Schulz et al., 2018).For instance, studies conducted in Turkey show that Erdogan has been frequently using the themes of "elites versus ordinary people" as well as "us and others"; thus, strategically promoting the opposition of Turkish society to others who are presented as hostile to national sovereignty and defining them as homogeneous categories (Erdoğan et al., 2018;Erçetin & Erdoğan, 2018).
In our integrative model (ISIMPL, see Figure 2), which is based on the social identity tradition, we utilise the dual-agency model of identity leadership and engaged followership developed by Haslam, Reicher, et al. (2022).Accordingly, we see populism as a mutual group process produced by followers and leaders, in line with research on identity leadership (Haslam et al., 2020;Steffens et al., 2014; also see Haslam, Gaffney, et al., 2022, for further information on the distinct approaches to leadership discussing identity leadership which understands leadership as a group process vs. leader identity, which focuses on understanding leaders as individuals (Epitropaki et al., 2017)).Contrary to most populism research, we are not making a distinction between top-down (e.g., structural features, organizational aspects, leadership) and bottom-up (individual aspects, attitudes, voting behaviour) populism, and instead, we integrate the dual-agency understanding to populism (leaders to followers and followers to leaders).Before explaining our model, we will briefly summarize the first studies that utilise the social identity approach in researching populism, and then we discuss the social identity approach to leadership, since they have an important place in our integrative model.
In recent years, there has been a significant number of studies addressing populism from a social identity perspective (e.g., Bos et al., 2020;Hameelers et al., 2019;Jetten, 2019;Jetten et al., 2017;Jetten & Mols, 2021;Mols & Jetten, 2016, 2020;Obradovic et al., 2020).For instance, Hameelers and de Vreese (2020) sought ways to combine the basic propositions about populism with the premises of social identity theory.Accordingly, they argue that there are vertical and horizontal outgroups against "the ordinary and pure people"; individuals' populist attitudes against these vertical and horizontal outgroups differ.Vertical outgroups are the "elites", the typical nemesis of traditional populist logic.Intergroup differentiation between ordinary people and vertical outgroups leads to anti-establishment sentiments and political distrust.On the other hand, societal outgroups based on cultural, ethnic, economic, or religious grounds are horizontal outgroups.Intergroup differentiation between ordinary people and horizontal outgroups lead to exclusionist populist attitudes.
The commonalities among definitions of populism also epitomize the three key components of populist attitudes: a Manichean worldview, an exaggerated belief in people's will, and anti-establishment rhetoric (e.g., Uysal, 2022).
In accordance with the Manichean worldview, populists usually define the people of a country as a homogeneous entity (Albertazzi & McDonnell, 2008) or monolithic group (Jagers & Walgrave, 2007).Accordingly, populist ideologies defend the idea that society is separated into two homogenous groups, one of which is good and the other, evil (Mudde & Rovira Kaltwasser, 2013).In general, elites are put on the evil side against the good, honourable, and aggrieved people of the society (Betz & Johnson, 2004;Jansen, 2011).
The Manichean outlook of populism combines people-centrism and anti-elitism.The construction of the elites as a nemesis of 'the people's will' by populist actors is also closely related to an anti-establishment sentiment and the belief in people's will.Although the rhetoric of 'general will' can resemble a pro-democratic discourse, populist leaders may aim to be the sole representative of the general will of 'the people'.Thus, they may see democratic values and institutions as an obstacle (see Barr, 2009;Schulz et al., 2018).In order to fight for these so-called 'democratic values' and attain the right of direct rule, populist leaders target feelings of deprivation.They point to the prevailing political system as the reason behind the deprivation, which is closely related to anti-establishment attitudes (see Golder, 2016;Pettigrew, 2017).Barr (2009) discusses how being a political outsider or feeling left out of power is interlinked with anti-establishment beliefs and support for populist parties.Anti-establishment beliefs are based on high shared public discontent with mainstream politics (Akkerman et al., 2017;Bakker et al., 2020;Barr, 2009).The basic idea behind this discourse and a shared set of beliefs is mostly based on the sentiments that elites in power cannot or do not represent ordinary people, hence, the ingroup ("ordinary people") should seek alternative political pathways such as unmediated direct rule of a populist leader or populist parties' strong opposition to mainstream politics.
This antagonism reflects an anti-elitism which is generally built on two social psychological mechanisms: (1) the relative deprivation that flows from the elite's repression of the "silent majority" and (2) moralization through social identity processes (e.g., self-categorization, identity leadership; also see Reicher et al., 2008) to differentiate "us" and "them" by attaching qualities such as purity and authenticity to "the people" on one hand, and immorality, non-nativism, and self-serving to "corrupt elites" on the other (Mudde, 2017).As we have established, the three components of populist beliefs (i.e., Manichean worldview, belief in people's will, and anti-establishment attitudes) can be explained by the core social identity mechanism of ingroup identification and intergroup differentiation.
Therefore, we can conclude that the studies that seek answers to what drives people to populist beliefs need an integrative social identity approach for populism.
However, this binary categorization may not always be enough to capture the complex nature of populist rhetoric.One of the most important features of populism is its elasticity which allows it to take the shape of cultural-political-religious patterns.While, in reality, the ordinary people may support elites (for arguments of System Justification Theory, see Jost, 2019;Jost et al., 2004), the responsibility for intergroup injustices may be horizontally attributed to other social out-groups who are historically and culturally suitable to be "enemies".In other words, populist leaders do not solely blame the elites, they also accuse refugees or other outgroups of taking from the ingroup's resources (Jetten, 2019;Rothmund et al., 2020).
Populist rhetoric is constructed around the idea that the "once upon a time" powerful group lost its position and became a victim (Reicher & Uluşahin, 2020).Oftentimes, populist rhetoric blames multiple groups at once.The "elite" are blamed for taking away what was rightfully the ingroup's.The other less-deserving groups are blamed for having what the ingroup deserves.And, at times, even the members of their wider ingroup are blamed for lacking loyalty to the ingroup (i.e., citizens of America who are not Trump's supporters, and 'weak Republicans'; Haslam, Reicher, et al., 2022;Reicher & Haslam, 2017).In these types of constructions of injustice, instability and crisis, minorities may become targets of populist rage as an outgroup (Jagers & Walgrave, 2007;Jay et al., 2019;Mols & Jetten, 2016;Pappas, 2014).In these contexts, the enemy poses a threat from both the horizontal (e.g., refugees) and the vertical (e.g., elites) level.Donald Trump's career as a politician is full of examples of this kind, but a tweet he posted on the 19 th of June 2018 will be sufficient for us to make our point.The tweet reads as: "Democrats are the problem.They don't care about crime and want illegal immigrants, no matter how bad they may be, to pour into and infest our Country, like MS-13.
They can't win on their terrible policies, so they view them as potential voters!" (Graham, 2018).Looking at the tweet, there is a clear construction of a threat defined by immigration which is used as a synonym of crime.The metaphor of "infestation" implies a healthy body losing its power due to foreign microbes akin to a powerful group losing its position and becoming a victim.Democrats -the "elites"-are blamed for allowing immigrants -the "less-deserving" horizontal outgroups-into the country to gain votes and grab power from those who actually "belong" there; making both elites and immigrants a target.On this theoretical basis, the mechanisms of identification with the ingroup and differentiation from the outgroup become pivotal to both the anti-establishment and the exclusionary dimensions of populist attitudes.
Hence, uniting citizens under the common ingroup identity of 'ordinary people' is one of the crucial successes of populist leaders.In defining this common identity, it is very important to emphasize the shared grievances of the ingroup and the systematic construction of the others who will act as scapegoats for these grievances (Hochschild, 2016;Inglehart & Norris, 2017;Jay et al., 2019;Norris & Inglehart, 2019).Given the fact that nativism, ethnocentrism, and authoritarianism are key correlates of populism (Mudde, 2004;Mudde & Rovira Kaltwasser, 2017;Van Assche et al., 2019), the national ingroup created by populist antagonism easily mobilizes against the non-native others who are responsible for the shared grievances and threaten the nativeness of the ingroup (Bieber, 2018;Bonikowski, 2017;Staerkle & Green, 2018).These 'others' usually consist of both elites and foreigners such as refugees (Bos et al., 2020;Brubaker, 2017;Hameelers & de Vreese, 2020).
By positioning the ingroup against vertical and horizontal threats, populist actors unite the citizens under a common identity and create a moral majority that can overcome economic and cultural divides (Jay et al., 2019;Jetten, 2019;Mols & Jetten, 2016).To this end, populist leaders frame the issues of inequality and representation of the prevailing liberal-democratic political system as irreconcilable differences between social identities.They emphasise the irreconcilable differences between groups by promoting intragroup homogeneity and intergroup differentiation (Bos et al., 2020).In other words, populism addresses individuals' shared grievances, while also promising positive self-esteem through virtue of ingroup membership (see Uysal & Düzen, 2021).The specific definition of the ingroup norms, morals, and values can then influence what is seen as being the representative behaviour of the ingroup, which can go in different directions including solidarity, but also collective hate towards the outgroup (see Reicher et al., 2005Reicher et al., , 2006)).The definition of these categories can become a tool to engage ingroup members in inhumane acts towards the outgroup and present them as 'virtuous' in the eyes of the ingroup (Reicher et al., 2008).These tools can be picked up by any populist leader who engages in blaming 'the other' for the ingroup grievances (see Haslam, Reicher, et al., 2022).For example, in the Capitol Riot, Haslam, Reicher, et al. (2022) argue that the violence that happened on 6 January 2021 reflected such dynamics.Similarly, the Nazi actions during the Holocaust, and the ethnic and religious violence in former Yugoslavia were seen by the ingroup members as virtuous and inevitably good (Elcheroth & Reicher, 2017;Koonz, 2003).This can be explained by the Five Step Model of the Development of Collective Hate (Reicher et al., 2008), which involves (1) ingroup identification, (2) exclusion of 'the other', (3) 'threat' caused by the outgroup, endangering ingroup identity, (4) presentation of the ingroup as uniquely good, and (5) the actions to eradicate the outgroup as the action to maintain the ingroup virtue.
In addition to the ideational approach to populism (Mudde, 2004(Mudde, , 2017;;Mudde & Rovira Kaltwasser, 2013, 2017), the discursive approach to populism (Hawkins, 2009;Jagers & Walgrave, 2007;Laclau, 2005) overlaps with the social identity framework of populism.For instance, Bos et al. (2020) argue that three types of populist communication create blame-shifting by social identity framing: anti-elitism, anti-immigration, and a combination of the two.Accordingly, we suggest that the social identity processes that increase the salience of ingroup identification and bolster out-group derogation or intergroup hostility (Mols, 2012) are behind the persuasive power of populist messages.In other words, there is a process that we call the "identity-framed populism loop": Populist messages construct the ingroup using shared grievances and blame-shifting (Bos et al., 2020;Hameelers, 2021;Hameelers et al., 2017) to communize worldviews by communicated group norms (Cohen, 2003) or "norm talk" (Hogg & Giles, 2012).Thus, salient ingroup identity increases similarity among ingroup members and intergroup differentiation and, in turn, strengthens the credibility of messages coming from the ingroup sources (Hogg & Reid, 2006;Mackie & Queller, 2000).Relatedly, recent research shows that populist messages blaming the elites are more persuasive among the high identifiers (Hameelers & Schmuck, 2017).When populist actors address the shared grievances or the societal inequalities by blaming not only elites but also refugees (Bos et al., 2020;Hameelers & de Vreese, 2020), citizens who share the group memberships and see the populist leaders as a member of this group, internalize this populist messages and mobilize supporters accordingly (Haslam et al., 2020;Hogg & Reid, 2006;Reicher & Haslam, 2017).

| INTEGRATIVE SOCIAL IDENTITY MODEL OF POPULIST LEADERSHIP
According to the social identity tradition in social psychology -the New Psychology of Leadership (NPoL;Haslam et al., 2020), identity leadership is viewed as a group process of mutual influence between leaders and followers who are members of the same social group (van Knippenberg, 2012).Therefore, populist attitudes which are often accompanied by nationalism and anti-immigration are seen as closely related to these group dynamics, rather than being related to the sole characteristics of the leader's charisma or personality (see Mols et al., in press).If we want to better understand populist leadership, NPoL (Haslam et al., 2020) can help us understand how leaders motivate followers to achieve the group's goals.The advantage of this approach is that it goes beyond explaining how populist leaders gain initial support and it allows us to consider the dynamic interactions between populist leaders and their followers over time.
Let us outline the key aspects of this approach, based on the leaders' ability to effectively build a mutual relationship with their followers, to motivate them to achieve ingroup goals and thus, achieve social influence over them (for a detailed overview of the NPOL, see Haslam et al., 2020).First, leaders must be seen as 'one of us', this is known as identity prototypiality.Prototypicality stands for the need for leaders to present themselves as members of the ingroup.However, while sharing similarities with the followers, leaders also need to be exceptional members of the group who are able to represent it well (Hogg, 2001;Turner & Haslam, 2001).In other words, leaders should be seen as representative of the unique qualities that define the group, as having the basic features that distinguish the group from the other groups -especially the outgroups -and should be perceived as a model members of the group.Research reveals that prototypicality is vital in order for someone to be recognized as the leader of the ingroup (Duck & Fielding, 2003;Platow & van Knippenberg, 2001).For example, people see the prototypical members as more credible (van Dijke & de Cremer, 2008), more capable (Steffens et al., 2013), and the most influential and effective leaders (Cicero et al., 2010;Fielding & Hogg, 1997;Giessner et al., 2009;Giessner & van Knippenberg, 2008;Hains et al., 1997;van Knippenberg, 2011).
Second, leaders need to achieve goals for 'us' via identity advancement.Identity advancement can be defined as a leader's capacity to achieve and advance the group's key goals and tasks, favour the group, defend the group's interests (rather than their own personal interests) even under threat, and preserve or enhance the group's prestige.
Research shows that potential leaders can become prominent if they can proceed with ingroup goals instead of their own goals (de Cremer, 2002;Haslam et al., 2020;Subašić et al., 2011;van Dick et al., 2018;van Knippenberg & van Knippenberg, 2005;van Vugt & de Cremer, 1999).In the case of populist leadership, the strategy of working against 'the elites', and the anti-political narratives of populist leaders' actions play a key role in effectively embodying this aspect of leadership (Eatwell & Goodwin, 2018).
Third, leaders need to 'craft a sense of us' through identity entrepreneurship (Reicher & Hopkins, 2001), which allows them to construe the meaning of what it means to be us and what it means to be them.It reflects the leader's ability to bring people together by forming a shared sense of "we-ness", making all members of the ingroup feel that they are part of the same group, creating and sustaining cohesion within the group, shaping and clarifying members' understanding of what the ingroup represents and does not represent by defining and shaping ingroup norms, values, and ideals.Research shows that the leaders who can craft an understanding of the group, that is, a sense of us (see Gleibs et al., 2018;Reicher & Hopkins, 2001;Steffens et al., 2013) become preeminent amongst the group members.
Fourth, the aspect of building a relationship between the leader and the followers is embodied by the identity impressarioship, in which leaders create events and ritualised group practises (i.e., rallies, marches) to celebrate the leader's visions and to collectively experience the sense of what it means to be a part of this social group.It reflects a leader's capacity to "embed a sense of us" by providing structures for operating the group well; engaging in activities and generating outcomes that allow the group members to live out their group membership in meaningful ways; to create material realities that are coherent with, and serve to embed, the social identity (Haslam et al., 2020;Steffens et al., 2014;van Dick et al., 2018).
Key aspects of NPoL are present in many classical definitions and descriptions of populism.This is especially true for ingroup prototypicality and identity entrepreneurship.For instance, effective populist leadership is generally defined as the ability to create a sense of "we-ness" among targeted citizens, bond them as a homogeneous group by addressing their moral superiority, and ensure their identification with the leader (Aslanidis, 2018;Erçetin, 2020;Wodak & Krzyanowski, 2017), consistent with the processes of identity prototypicality and entrepreneurship.Moreover, recent research shows that voters of the populist leaders are convinced that their leaders are not part of the current political establishment which is seen as the reason for people's deprivation (Silva, 2019).In other words, the mobilization power of populist leaders lies in their ability to convince people that "I am one among you, not them" (Kotwas & Kubik, 2019).
In addition to being a prototypical member of the people, the populist leaders should be identity entrepreneurs who create homogenous and evil others, and embed the image of these evil others among the understandings of ingroup members (Pappas, 2014;van Kessel & Castelein, 2016).Populist leaders who are identity entrepreneurs frequently use blaming discourse to build others as an outgroup and create intergroup differentiation between ingroup and outgroup (Hameelers, 2021;Hameelers & Schmuck, 2017;Lozada, 2014;Vasilopoulou et al., 2014).Blaming discourse both ensures the moral superiority of the ingroup and justifies the exclusion of others.Moreover, blaming discourse may serve as a tool for creating intergroup threats among ingroup members (Hameelers et al., 2017;Hameelers & Schmuck, 2017;Matthes & Schmuck, 2017;Reinemann et al., 2017).Since "populist framing begins by making context-based inter-group distinctions" (Erçetin, 2020), promoting fear-based scenarios through perceived intergroup threat and offering their leadership as hope is the core mechanism of populist leadership.
Similarly, recent work on identity leadership has focused on understanding the aspects of identity entrepreneurship.For example, a study by Maskor et al. (2021) analysed the attack rhetoric of Donald Trump and Hillary Clinton during the US 2016 Presidential Election.Whereas Trump portrayed Clinton in his rhetoric as the representative of the corrupt elites, Clinton tried to influence female voters by emphasizing Trump's misogynist comments and his inappropriate behaviour towards women.Maskor et al. (2021) thus proposed that in addition to creating a sense of us and them through rhetoric, leaders also engage in attack rhetoric towards their rivals, which leads to leadership destabilisation and potentially increases their social influence over the group which they are trying to mobilize.In the psychological sense, leaders can engage in defiling, devaluating, dividing, and destroying a shared sense of "us-ness" (Maskor et al., 2021; in the case of Trump and Clinton this was targeting the values and goals of 'Americans').A key aspect of this destabilisation rhetoric, to which populism is closely linked, was the speakers' emphasis on their opponent candidate's past failures.Accordingly, Maskor et al. (2021) introduced an important novel approach towards understanding how the principles of identity leadership can be used by populist leaders to destabilise opponents, undermine their social influence, and spread anti-establishment and anti-elitist sentiments.
We argue that based on this work, it is important to further understand these wider dynamics between leaders, followers, and leaders' opponents.Thus, when considering these rhetorical attacks, it is important to notice that populist leaders not only employ the use of the traditional outgroups (i.e., elites) in their attack rhetoric, but they also focus on embodying the negative connotations associated with the outgroup in a single individual who is often not an enemy from the outside of the country (i.e., refugees, migrants) that we would traditionally expect, but an enemy from within the one's ingroup country (i.e., the Democrats such as Clinton, Obama, and Biden, but also "weak Republicans" for Donald Trump; see Haslam, Reicher, et al., 2022;Reicher & Haslam, 2017).This opens the space for investigating how political leaders not only construe their own social influence using the tools of identity leadership to mobilize support but also undermine the influence of mainstream opponent leaders (i.e. as Trump did with Clinton; also see Mols et al., in press).
Considering that populism is a term often ascribed to political rivals as a strategy for leader destabilization, the question of who deserves this label and why becomes critical.A leader's status as a populist is subject to change, open to interpretation and most of the time based on an outgroup's judgement.Therefore, we believe that populist leadership should be analysed as a political strategy that can be adopted by any political leader from time to time, rather than a stable leader characteristic, according to the principles of identity leadership.It is true that populist mobilization strategies are adopted by some leaders more frequently and in more destructive ways than others.
However, we believe approaching populist leadership using a process analysis rather than a leadership analysis is more beneficial in developing an overarching social-psychological understanding of populist zeitgeist and political cleavages boosted by populist strategies.Confining the analysis of populist leadership to "populist" leader characteristics could lead to three problems: (i) overlooking the intragroup process and leader-follower interactions; (ii) emphasis on misleading commonalities between leaders who adopted populist strategies from time to time while hindering the development of further analysis of different leadership styles beyond populist commonalities; and (iii) taking the easy way out by employing populism and populist leadership to explain 'hard' questions of social psychology such as identity formation, mobilization of hate and solidarity.Hence, we believe that social psychology should approach populism and populist leadership as popular political strategy that impacts intergroup relations and politics; neither as narrow as a leader's characteristics nor as broad as basic social-psychological mechanisms of group dynamics.

| POPULIST LEADERSHIP AND NATIONAL IDENTITY: RECENT CASES
Populism as an ideology often thrives on hate, and we have witnessed many instances in which far-right populist groups often endorsed the hateful ideology and used it to create their narratives of being the 'victims' of a system (Reicher & Uluşahin, 2020;Sirotnikova, 2021).According to the social identity approach, the content of what it means to be 'us' and what is seen as a moral to 'us' can be rhetorically shaped by leaders and then endorsed by followers (i.e., Hitler's vision of Germany endorsed by Germans; Elcheroth & Reicher, 2017).Similarly, if we want to better understand the mobilization rhetoric which populist leaders use, we need to consider the role of national identity (Reicher & Hopkins, 2001) in it, as we know that populist rhetoric tends to be associated with using the narratives of the national past to present the us versus them distinction in a contextual and relatable way to the ingroup members (i.e., the narrative of American Jeremiad used by Trump; Reicher & Haslam, 2017;also see Bercovitch, 2012) and allows leaders to better place their arguments within the wider cultural-historical context (Reicher & Hopkins, 2001).
For example, populism in Slovakia, especially in the case of the national-populist party People's Party 'Our Slovakia' uses the historical narrative of Slovakia's independence as a Nazi state during World War II, to claim that this era was 'the only true independence of Slovakia as a nation' (Sirotnikova, 2021).Using this narrative of 'national independence' to celebrate and rally around the national symbols and national heroes is a key strategy of this particular form of the populist movement.On the other hand, populism in Hungary makes use of a different historical period as the origin of the division between 'us' and 'them', upon which the destabilisation rhetoric is based.After the fall of 'communism' in 1989, the information from the archives about people's membership in the Communist Party has never been fully recovered (Visnovitz & Jenne, 2021).Victor Orban uses this strategy to discredit the opposing parties by accusing them of having a history of being members of the Communist Party, which is nowadays presented as an "enemy" in Hungary.
Thus, attack rhetoric investigated by Maskor et al. (2021) might be one of the ways of how leaders undermine the influence of their opponents.Especially in cases such as Hungary, where populist leadership also builds upon institutional power arising from the leaders' ability to use censored information and strategically demobilise their opponents (i.e., by not allowing the public to access the information in the archives).To fully understand the range of strategies that populist leaders use to undermine the influence of their opponents, we need to look beyond the Western context, which allows us to consider the populist rhetoric along with the practical demobilisation strategies used in non-Western contexts (see Moss, 2019;Reicher, 2019 for similar arguments).
Another strand of research has focused on identity impressarioship.For example, Reicher and Haslam (2017) have described Trump rallies as "festivals of identity", meaning that Trump was able to create events in which he presented his vision of future America and allowed the followers to celebrate this vision and, in turn, experience a sense of shared identity in a real-life event.Trump uses a specific type of rhetoric of decline called American Jeremiad (Bercovitch, 2012), in which he presents America as a nation that has declined due to the action of their 'enemies' (i.e., China, Mexico).However, beyond the use of rhetoric, the rallies themselves were orchestrated to embody this narrative and Trump presented himself as a person who is able to overcome these issues and solve the problems of his supporters.This is embodied in the atmosphere and staging of his rallies, and demonstrates that future research needs to focus more on this aspect of identity leadership to better understand how populist leaders construct events for making their visions real, allowing the followers to experience this in a collective way (see Jurstakova et al., 2022).
In addition, as previously discussed, leadership is a function of building and maintaining a positive relationship with followers.After the Capitol Riot (6 January 2021) and following the Trump's Second Impeachment trial (February 9-13, 2021), scholars have attempted to explain the dynamics of leadership and followership in the violent attack of Trump's supporters on the US Capitol Building in Washington DC (Haslam, Reicher, et al., 2022).Although it can be argued that, in the last years, many populist far-right groups have been mobilising themselves and engaging in often violent behaviour (i.e., Charotesville's 'Unite the Right' rally, 2017), and that many of such groups planned to engage in violence during January 6th (Wamsley, 2021), the presence of Donald Trump and his speech given before the invading of the Capitol building presents a situation in which the role of leaders and followers can be investigated.Haslam, Reicher, et al. (2022) suggest an explanation through a dual-agency model, which allows us to understand the actions of followers as a process of the co-production between leaders and followers.From this perspective, Trump did not have to specifically instruct the crowd to attack the Capitol building.His role was mostly in engaging with followers and building this mutual process of identity enactment.He created a space where the followers felt that they were heard and that their grievances were valid.This led the followers to think that "our president wants us here" (Barry et al., 2021), which nicely illustrates the concept of engaged followership (Haslam et al., 2020; also see Haslam, Reicher, et al., 2022).
Engaged followership is a concept against that argues that followers blindly follow the orders of authority (i.e., populist leaders), but that they base their actions on what is consistent with the ingroup norms and values, while also being innovative and creative in the ways of enacting the shared social identity (Haslam & Reicher, 2017).This was why it is possible to argue that the delay in Trump's denouncement of the insurrectionists played an important role in the acceleration of the events.Therefore, the dual-agency model of identity leadership and engaged followership developed by Haslam, Reicher, et al. (2022), similarly to previous work on people's (dis)obedience to authority (Haslam & Reicher, 2012), explains that leaders can create situations in which followers can enact their shared identity in creative and sometimes unexpected ways.The Capitol Riot, discussed by Haslam, Reicher, et al. (2022) should be considered as an illustration of this dynamic interaction between leaders' actions -such as Trump giving a speech at 'Save America Rally' near the US Capitol building on 6 January 2021, and the attack on the US Capitol building on 6 January 2021 by Trump supporters and various right-wing groups.The events that unfolded were a co-production between leader and followers, based on the leader's ability to create a sense of togetherness, create ingroup norms and goals, and outline the necessary action to achieve these goals.On the side of the followers, it was about embracing the shared identity, understanding the action and goals, and creatively working towards the leader (Haslam, Reicher, et al., 2022; also see Haslam et al., 2019;Haslam & Reicher, 2012).

| CONCLUSION
Approaching populism as a social-psychological concept will enable us to understand contemporary societal conflicts by capturing how ingroup identity and a collective victimhood narrative are constructed among certain groups and spread as populist mobilization into the intergroup contexts via social identity leadership.Our review argues that NPoL (Haslam et al., 2020) can provide the theoretical basis to examine how populist mobilization occurs as an intraand intergroup process and suggests the Integrative Social Identity Model of Populist Leadership.We further discuss that theorizing and researching identity leadership needs to go beyond the interaction between the ingroup leader and followers and discuss the role of the outgroup leader and outgroup members, and the long-term development of these processes across wider contexts.We believe that our review is the first step in this direction.

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