The contemporary market model of democracy has led to the political and economic exclusion of popular sectors. Its adoption by both Left- and Right-parties has fostered a widening legitimacy crisis for democracy as it exists today. As such, the central concerns of this project are to identify how and why an alternative model that simultaneously boosts the political and social citizenship of popular sectors may emerge, develop, and sustain itself. A theoretical framework is advanced, detailing how the changing relative power of a Left-led state, the organised popular base, economic elites, and international (f)actors facilitate, shape and limit opportunities for democratisation. The framework is applied to the cases of Bolivia and Venezuela where radical-substantive democratisation experiments were undertaken since the turn of the millennium. The lesson from the two cases is that substantive democratisation that extends social and economic citizenship, thereby challenging entrenched elite interests, will foster an economic-elite destabilisation backlash. Progressive governments in both cases faced tensions between adhering to the popular mandate to boost political and economic inclusion on the one hand, and working within the confines of a national, regional and global environment dominated by the forces of capital on the other. A second and related tension thus emerged between strict adherence to the liberal democratic separation of state powers, and centralisation of power in the office of the executive to overcome elite barriers to the democratisation processes. While the presidents argued that centralised power would be used in a progressive manner to block elite destabilisation efforts while simultaneously opening new avenues for direct participation from below, over time the power imbalance between the political leadership and the organised base led to a fractured relationship between these two groups. In some scenarios, the base faced co-optation if they worked too closely with the state, while in others, retaining an autonomous critical stance toward the government fostered state-led divide-and-conquer tactics of formerly powerful popular organisations. The emergence of a “dual power” of two lefts whereby the Left-government entered into confrontation with the popular base greatly weakened the democratisation process, allowing elite and transnational forces to take advantage.