The authors begin from a methodological premise drawn from process-tracing, a qualitative technique refined over the past decade that shifts analytical focus away from causes and outcomes and toward the mechanisms that link them. As they explain, drawing on the framework of Beach and Pedersen, process-tracing allows scholars to trace causal mechanisms through detailed within-case empirical analysis, theorizing how causal forces are transmitted in the space between cause and effect. Rather than treating populism as a self-evident category, the researchers use this method to ask a deceptively simple question: what actually happens in between the structural conditions that favor populism and the emergence of populist leadership? Their answer, developed inductively from three influential prior studies, is fundamentally organizational.

The three studies at the core of the analysis come from Kirk Hawkins, Benjamin Moffitt, and Robert Jansen, each of whom conceptualizes populism differently. Hawkins treats populism as a discourse or worldview, measurable through holistic grading of political speeches, and locates the causal mechanism in the way populist ideas are translated into organizations—most notably in his account of Venezuela’s Bolivarian Circles, the grassroots groups that spread the Chavista political project and mobilized supporters, alongside the electoral vehicle Movimiento Quinta República that carried Hugo Chávez to the presidency in 1998. Moffitt, by contrast, defines populism as a political style built on the dichotomy of extraordinariness and ordinariness, in which leaders perform crises for audiences through media, making the mediated social tie between performer and public the outcome. Jansen reconceives populism as populist mobilization—a sustained, large-scale political project that mobilizes ordinarily marginalized social sectors into publicly visible and contentious political action—placing the mechanism just before mobilization materializes, in the construction of hierarchical parties staffed by dedicated supporters who co-opt or politicize preexisting grassroots organizations.

Despite their differences, the three approaches converge on a crucial insight: in every case, a leader depends on a staff of dedicated supporters and on organizations to sustain the connection with the people. abstracting from these commonalities, Poblete and Contreras construct a theoretical causal model in which causes fall into three types: deeper-ultimate structural causes such as culture and belief systems, surface-proximate structural causes such as political, demographic, and economic conditions, and agency causes, principally leadership. The outcome they define is populism understood not as discourse or style but as a populist social tie—a reciprocal, emotionally loaded relationship between leader and supporters that draws on the sociological tradition of strong versus weak ties and on Ostiguy’s distinction between the high and low dimensions of political life, where the low end is the domain of direct, personal, emotional connection.

The causal mechanism they abstract unfolds in three successive stages. In the building stage, a leader makes initial contact with closest supporters, and together they begin disseminating a political project grounded in ideas about how the country ought to be. In the development stage, these proto-organizations—often elitist and frequently military in origin—are transformed into parties, unions, and grassroots organizations that can reach national power. In the consolidation and mobilization stage, the leader and these organizations conduct presence-based political actions such as rallies, marches, and door-to-door proselytism, or mediated actions including radio and television appearances and, more recently, social media advertising and the use of social bots, all aimed at converting potential adherents into an active support base.

To test this mechanism empirically, the researchers selected first Peronism (1943–1955) as a paradigmatic typical case, with further references to first Varguism in Brazil (1929–1945) and Chavism in Venezuela (1982–2013). The evidence comes from historical scholarship that draws extensively on primary sources, chosen for their relevance to the periods under study. The building stage is visible in Juan Perón’s pre-1943 links with nationalist army officers and, during the 1943 dictatorship, his close tie with Colonel Domingo Mercante, who provided access to La Fraternidad, a major socialist union of railway workers, and with the prominent union leader Ángel Borlenghi, who later became Minister of Interior Affairs. Comparable patterns appear in Brazil, where Getúlio Vargas moved from military support among the tenentes to a unionized base under Labor Minister Alexandre Marcondes Filho, and in Venezuela, where Chávez’s closest partner was the former military officer Diosdado Cabello, later complemented by ties with unionist Nicolás Maduro.

The development stage is illuminated by the case of the GOU (Grupo de Oficiales Unidos), founded in 1943 when army officers secretly met at the Hotel Conte near the Plaza de Mayo in Buenos Aires. Perón himself headed the initiative, connecting disparate motivations—rejection of communism, resentment of political interference in the Army, and the prospect of electoral fraud—into a coherent ideological project. The GOU became an internal spy ring watching over the officer corps, and its influence propelled Perón through the military hierarchy until, by mid-1945, he had dramatically shifted his support organizations from a small military-based group to an electoral platform with a large union network. The Labor Party, designed by Borlenghi and other union leaders including Cipriano Reyes, was built through unions that were already widely developed before Perón’s rise—a contrast with Jansen’s Peruvian case, where parties organized and co-opted non-partisan organizations. In Brazil, where unions were fewer, Vargas’s Labor Minister Lindolfo Collor issued decrees to control and create them, delivering benefits such as consumer cooperatives, loans, legal assistance, and education to pro-regime unions. In Venezuela, Chávez pursued an ambivalent strategy of co-opting powerful petroleum-sector unions while simultaneously building the Bolivarian Circles to incorporate informal workers, who constituted nearly half the workforce before his government.

The consolidation stage is exemplified by the events of October 1945. After the Army pressured the government to dismiss Perón from his Labor Department post, unions and Mercante reacted on the morning of 12 October, meeting roughly eighty union leaders and agreeing on a general workers’ rally. On 17 October, an ecstatic crowd filled the Plaza de Mayo demanding Perón’s release from imprisonment, and the government chose a peaceful solution: Perón appeared on the balcony of the Casa Rosada and called for a calm withdrawal. The authors read this rally as an outstanding example of populist mobilization and a turning point in the transition from military to unionized organizational bases. Similar mobilizations occurred elsewhere with different results: in 1945, thousands of Brazilian unionized workers protested under the motto Queremos Getulio but failed to prevent Vargas’s deposition, while in Venezuela in 2002, a coup against Chávez was repelled thanks to grassroots organizations, especially the Bolivarian Circles commanded by Cabello, alongside a large part of the Army.

The resulting refined mechanism, presented in systemic fashion, distinguishes the three stages by their different natures: an initial association between leader and closest supporters that does not yet constitute a full political organization; the construction of organizations proper, beginning with smaller, often clandestine military groups that are useful for conspiring and executing coups, followed by parties, unions, and grassroots organizations that are networked and hierarchically controlled by the leader; and finally the formation of broad social bases through political mobilization. The hallmark of Latin American populism, the authors argue, lies not in forging a distinctive populist organization—such organizations appear across different regimes—but in a specific organizational pattern: highly vertical organizations configured in a hierarchical, networked manner extending from the leader through the State, in contrast to more horizontal party structures such as Spain’s Podemos.

The study’s most striking revisionist claim concerns chronology. By tracing the organizational inception of Peronism, the authors challenge the consensually accepted founding date established by historiography. What enables political mobilization and sustains the populist social tie over time, they argue, is its organizational support, which begins in 1943 at the Hotel Conte rather than on the balcony of the Casa Rosada on 17 October 1945. The year 1945 marks the onset of Argentine populism as a mass phenomenon, when reciprocity between Perón and his people first fully crystallized; 1943 marks the onset of the causal mechanism connecting causes to that outcome. The same logic dates the development stage of Chavism’s mechanism to the founding of the MBR-200 in 1983, and Varguism’s to 1929, when Vargas first met the officer Luís Carlos Prestes in Rio Grande do Sul. The authors also chart paths for future research, including testing the mechanism in less-typical cases such as Aprism in Peru or Correism in Ecuador, and investigating how audiences are persuaded by leaders—a dimension they note remains understudied, with mainstream research examining discursive messages sent to what Ostiguy calls blank subjects. By shifting attention from what populism says to how it is organizationally built, the study offers an alternative explanatory framework for one of the region’s most enduring political phenomena.

Subject of Research: Causal mechanisms behind the establishment of populism in Latin America

Article Title: How populisms are established: political organizations and leadership in Latin America

Article References: Poblete, M. E., & Contreras, C. (2026). How populisms are established: political organizations and leadership in Latin America. Frontiers in Political Science, 8, Article 1611699. https://doi.org/10.3389/fpos.2026.1611699

Image Credits: AI Generated

DOI: 10.3389/fpos.2026.1611699

Keywords: populism, Latin America, political organizations, leadership, process-tracing, Peronism, Chavism, Varguism, causal mechanism, social tie, political mobilization, Frontiers in Political Science