The introduction chapter critically reviews the existing literature and introduces a theory of mediated threat, which explains how perceived threats to civic freedoms and institutional autonomy can motivate the masses and reshape the relational structure of the democratic opposition. Our basic proposition is that threats do not instantaneously provoke protests; rather, they require perception and socialization among citizens to potentially trigger mobilization. Different groups of citizens may perceive the same threat in disparate ways, leading not only to varied mobilizational responses but also the formation of new organizations and groups. This alters the relational dynamics of the opposition through which new threats are assessed.