The Arab Uprisings of 2011 posed some serious challenges to conventional wisdom in political science research about the durability of authoritarian rule in a region that was once thought of as exceptionally resistant to democratic development. Relatedly, the uprisings brought to light a host of actors, processes, and relationships that were at the peripheries of theoretical discussions on authoritarian politics. Among these actors are protest movements organized around loose, non-hierarchical networks and that operate outside of the realm of formal organized politics. Using an inductive study of the case of Egypt between 2011 and 2013, this paper attempts to theorize the role of protest movements in the Arab Uprisings and, accordingly, identify a set of research agendas aimed at enhancing the theoretical and historical depth of our understanding of the origins of the uprisings, as well as the divergent trajectories they followed. The paper argues that in the particular case of Egypt protest movements played a major role in aggregating a variety of political and economic grievances that were crowded out of formal opposition politics in light of the growing irrelevance of opposition political parties as a result of cooptation and repression. During the lead-up to the uprising, such movements also played a role in politicizing a variety of social and economic agendas that traditionally fell outside of purview of formal politics. While protest movements were essential to setting the permissive conditions for the popular mobilization that occurred in the winter of 2011, evidence from multiple experiences of nation-wide protests between 2011 and 2013 suggest that the sustainability of mobilization—and thus the likelihood that it could generate sufficient pressure on the state—is largely dependent on the short-term support it receives from organized political groups and actors that normally occupy the formal political sphere. Evidence also suggests that the loose, non-hierarchical modes of organization that these movements adopt have made them more resistant than formal political organizations to authorities’ strategies of cooptation and repression. Yet these same structures have also limited the capacity of such movements to participate effectively in formal politics during the post-Mubarak period. Thus, the paper argues that these trends enhance our understanding of the major paradox of the Egyptian uprising, namely: powerful waves of popular mobilization that are able to extract short-term concessions from the ruling authority, but ones that are unable to effect meaningful long-term changes in the realm of formal politics.