There has been an ongoing debate in the literature about the extent to which the European Commission is a political actor, sets the European political agenda, mediates intra- and interinstitutional conflicts, and represents the interests of the European community. The lack of a clear hierarchy among the European Union’s core institutions, along with its complex, fragmented, and pluralistic leadership structure, further complicates the picture, resulting in intense debate about the distribution of power within the union.

Henriette Müller approaches this conversation from the “actor-centered perspective of political leadership” (p. 24). By examining the power and influence of Commission presidents, she sheds light on their oft-cited but little understood role. As “the only position that participates in all four arenas of European decision-making” (p. 15), the Commission president speaks for Europe and fulfills important political functions, from agenda setting and consensus building to policy management and implementation. Constrained, however, by weak institutional powers and an unstable situational context, Commission presidents must often rely on their own personal skills and connections to provide meaningful political leadership.

Because the existing literature has paid relatively little attention to this anomaly, Müller investigates the reasons Commission presidents differ so significantly in their ability to tackle the inherent limitations of their position and fulfill their three core responsibilities: policy formation (agenda-setting leadership), policy implementation (mediative-institutional leadership), and policy (re)presentation (public leadership). Müller’s analysis centers on the factors that make political leadership in supranational governance successful and explains why some Commission presidents act as “true president[s] of Europe,” while others fail to overcome the challenges and complexities of the office.

In the first two chapters of her book, Müller presents the theoretical background of the study by introducing the four patterns of political leadership performance (strong-entrepreneurial, moderately strong-executive, moderately weak-reactive, and weak-passive/nonleadership) and the interactionist approach that highlights the “relationship between individual actors and the institutional and situational context they are embedded in” (p. 19). The next three chapters meticulously evaluate the leadership performance of three Commission presidents whom she selected for their “empirical compatibility, representativeness, and variance with regards to … personal (pre-)dispositions” (p. 10): Walter Hallstein (1958–67), Jacques Delors (1985–95), and José Manuel Barroso (2004–14). Applying the most similar systems design, Müller engages in a systematic comparison of their political agendas as well as their mediation, reconciliation, and public outreach efforts. Analyzing more than a thousand presidential speeches, countless internal and formal Commission documents, newspaper articles, and interviews of civil servants, she concludes that in supranational governance, institutional structure, and situational setting are less important than (1) the type of political agendas set by incumbent Commission presidents, (2) the way presidents interact with the Council of Ministers, the European Council, and the European Parliament, and (3) the extent to which they gain and maintain public attention and create a positive public image.

Müller does not conduct a quantitative analysis of presidential influence on the legislative priorities of the union, but she introduces a new approach to the much-debated question of which actors and institutions shape EU policies. Rejecting exclusively political and technocratic depictions of the Commission, she presents an alternative to mainstream understandings of the interinstitutional balance within the European Union and demonstrates the importance of a technocratic-political career profile. Müller’s work is a valuable addition to the literature in two important respects: First, her comparative study of presidential powers and leadership styles contributes to ongoing debates on EU leadership and the Commission president’s power and influence vis-à-vis the Commission and other core EU institutions. She demonstrates rather convincingly that in situations of weak institutional power and structural uncertainty, robust and visionary leadership can positively impact both political outcomes and help the Commission adapt to the perennial challenges of the EU politics. Second, by offering a framework for evaluating leadership performance, she effectively merges the fields of European studies and leadership studies, thereby advancing knowledge in both areas and laying the groundwork for further examination of leadership performance in the supranational and international contexts.

Müller’s detailed analysis supports her argument that “Jacques Delors provided a focused political agenda with an innovative impulse, as well as an active meditative-institutional and positive public leadership, [and thus] his performance falls under the strong-entrepreneurial leadership type” (p. 219). However, her largely negative assessment of Barroso’s presidency directly contradicts that of Kassim (2013), who regards Barroso as a strong, preeminent, and innovative Commission president. Moreover, her focus on the three presidents’ personal attributes and leadership styles leaves a number of key questions unanswered: Are changes in a president’s ability to exercise political leadership over time solely a consequence of individual capabilities and personal (pre-)dispositions? Do the strong centrifugal pressures in the Commission and ongoing presidentialization impact the leadership styles of incumbent presidents? To what extent do formal (and informal) presidential powers vis-à-vis those of the Commission as a whole affect leadership performance?

Müller argues that “treaty changes hardly altered the balance of power between the Commission presidency and the European Council, the Council of Ministers, and the European Parliament” (p. 3), but other studies, especially those focusing on presidential agenda-setting powers, reach different conclusions. Institutional tension is not new to the European Union, but the European Council’s creation of a permanent presidential position seems to have exacerbated the situation. For instance, the infamous “Sofagate” incident of 2021 revealed that the power struggle between the presidents of the European Council and the European Commission has intensified in recent years. Müller’s work would have benefitted from a study of the powers of the Commission president in relation to that of the Council president, rather than in isolation.

Müller’s within-case analyses do not control for the different challenges each president faced, and her otherwise excellent study does not always explore the changing institutional dynamics or the increasingly complex demands of the European community. Treaty amendments and the increased politicization of EU issues remain largely exogenous to the analysis, leaving unanswered questions about how events like the Luxembourg Compromise and the sovereign debt crisis affected the Commission presidents’ ability to perform their leadership duties. More work may be needed to conclude if urgent crises resulted in more cooperation, and determine what factors make Commission presidents more likely to overcome the constraints of their institutional and situational contexts (rather than simply choosing to cooperate). Müller’s codification of each president’s speeches, priorities, and preferences could be a valuable resource for a follow-up study quantitatively analyzing whether, or to what extent, the European Union’s legislative output correlates to the three presidents’ ideal policy outcomes. This empirical test would serve as another measure of success, comparable to the binary assessment of central tendencies Müller identifies in her case studies.

Political Leadership and the European Union Presidency is essential reading for those interested in the intra- and interinstitutional relations of the European Commission and “what makes political leadership in supranational governance successful” (p. 5). Müller’s rich and diverse empirical content and in-depth analysis will enhance the debate about the strategies leaders use to achieve goals, garner support, and mediate and build consensus; it will also serve as a valuable source of information and even inspiration for political actors.