Purpose Due to new regulations, changing customer preferences and strategic reorientation, the role of responsible decision-making has become increasingly complex for both small and large firms. In relation to this, this article contends that companies are turning into political actors with political responsibility for sustainability-related issues in their supply chain and beyond. Therefore, this article aims to investigate (1) how companies have become political in their supply chain and (2) which mechanisms contribute to this development. Design/methodology/approach To investigate the political nature of companies in their supply chain, this research draws on a critical realist case study inspired by process tracing. A total of 30 interviews were conducted with actors from within global coffee supply chains to get a wide overview of the different perspectives on how coffee companies deal with political complexity. Findings It is found that companies in the coffee supply chain are increasingly acting like traditional political actors. Their engagement in political activities emphasizes three contextualized causal mechanisms driving this transformation: (1) customer pressure, (2) attention to trust and transparency and (3) personal motivation. Research limitations/implications The results point to the political nature of companies’ supply chain management (SCM)-related activities, indicating they should recognize that their role in the supply chain gives them the capacity to act as state-like actors. Originality/value Political SCM is introduced as a new conceptual element in the SCM discourse by defining the term “political” and linking political theory and sustainable SCM literature. This provides a better understanding of SCM and offers guidance on how SCM can be understood as a set of political activities.