In the Brazilian Amazon, governance reforms that cater for both, the needs of poor smallholders and environmental concerns are frequently exposed to a challenge: Those who pursue environmental destructive activities on a large scale often have close ties to decision makers at various administrative tiers. This makes it difficult for those who suffer from these land use activities to make their claims being heard in processes of institutional change. The example of forest tenure reform that protects smallholders from land invasions is used to analyse institutional change under these circumstances. It builds on a comparative case study approach drawing on five tenure reform initiatives in the federal state of Pará. Data was collected from 2006 – 2008 and analysed using a hermeneutic approach that builds on existing theories and allows for the emergence of empirically informed codes. Results show that smallholders are marginalised in local politics. Ranchers or logging companies are closely related to municipal politicians making it difficult for poor resource users to achieve governance reforms that would reflect their needs. To overcome their marginalised position, poor smallholders need to rely on civil society movements and alliances capable of taking their struggle to the federal level. Environmental NGOs are essential to achieve this. This emphasises the role of power in bringing about environmental governance reforms. Efforts to change environmental governance need to address its political nature and employ measures to support local civil society movements during these processes. The paper reports on the dynamics of tropical forest governance in a context characterised by inequality in access to political fora. It suggests a framework to analyse the ways power influences governance reform processes. This highlights the challenges smallholder communities need to confront when striving for inclusive environmental governance regimes.