The following study aims at, from an external organizational perspective, examining whether, and if so, how differences in strategic party behaviour can be explained through differences in political leadership style. To provide an answer to the research question the study adopts a qualitative approach using a theoretical thematic analysis. The study proceeds from the phenomenon of personification of politics and methodological individualism to explain the importance of examine political leadership in studying political party behaviour. In order to illuminate presumptive differences in political leadership style, the study adopts Burns (1978) theoretical distinction of transactional and transformational leadership. To also illuminate presumptive differences in strategic party preferences, the study moreover adopts Müller & Strøm’s (1999) conceptual framework of party goal theory. The theoretical framework is empirically applied to the party leadership of the Swedish Left-party during the government formation in January 2019 and the following government crisis in the summer of 2021. This enables the study to examine two different party leaders since the party changed their leader in the mid of the term of office. The study demonstrates differences in the party’s strategic behaviour in relation to the government formation and the following government crisis, which stems from changes in the party’s ambition of office-seeking. Furthermore, the study also demonstrates differences in the leadership styles that are exercised by the different party leaders from the theoretical application of transactional and transformational leadership. The study suggests that these findings are interrelated, meaning that the exercise of a certain leadership style will also imply differences in party behaviour.