After almost two decades of praise for Indonesia's democratic achievements, a scholarly consensus has begun to emerge that Indonesian democracy is in regression. In this article, we consider the sources of that regression. Drawing upon the comparative literature on democratic decline, we propose that Indonesia is an illiberal democracy, and argue that a constellation of structural, agential and popular forces has led to an incremental deterioration in democratic quality. We first reaffirm arguments that trace the origins of contemporary democratic weakness to the nature of Indonesia's transition, and the incorporation of anti-democratic elites into the governing structures of its democracy. We then show how Indonesia's two most recent presidents each eroded democratic norms and institutions in pursuit of political security. Finally, we cast a critical eye on the widely shared view that Indonesia's population is a bulward of democratic. While most Indonesians support democracy as an abstract concept, significant parts of the population show limited support for the protections, checks and freedoms that underpin a liberal democracy. We suggest there is a significant constituency for illiberalism in Indonesia, and point to the presence of a conducive electoral environment for further democratic erosion.