Peru has long had to contend with a lack of national and political integration. Yet its APRA party is the oldest mass-based reformist party in the region, and its mission has historically been to integrate the nation. The APRA, since its inception, aroused more political hostility than any other force in Peru, and consequently was repressed, even outlawed, for decades. Years of repression and clandestinity contributed to a lack of doctrinal clarity and undemocratic tendencies within the party, which were to affect its capacity to govern. The nature of the party, and the difficulty of its task, are the subject of this thesis. Despite the existence of democratic institutions, large sectors of the population exist outside of formal legal, political, and economic systems; there is a gap between state and society. Successful democratic reform would incorporate these marginalized sectors. When the APRA came to power in 1985, it proposed to do so by focusing on the needs of the poorest. Expectations were high for the new government, in part because of its popular young leader, Alan Garcia, and in part because a decade of economic and social crisis had discredited both the military and the right as alternatives, resulting in unprecedented consensus for reform. Once it attained power, the APRA managed, for the first two years, to maintain support that was unique to reformist efforts in Peru. A sudden shift in strategy to confrontational rhetoric and authoritarian tactics destroyed the fragile consensus necessary for democratic reform. The politics of reform became the politics of polarization: a "winner take all" style debate in which cooperation and compromise were impossible. The outcome was policy stagnation, a surge of reaction from extremes of the left and the right, and severe strain on the political system. The APRA party, rather than playing the role of the strong centre acted as a catalyst to the polarization process. In large part due to decades of sectarian and authoritarian strains that the party's 1980's renovation had not eliminated, it was virtually powerless in the face of increasingly erratic behaviour on the part of its leader. This thesis examines the evolution of the APRA from the time of the 1968 military "revolution" through the party's first three years in power. It explores the formulation and initial success of the consensus it built, the reasons for its breakdown, and the fate of the poor during that process. The difficult context in which the party had to operate will also be addressed. Finally, it attempts to contribute to the understanding of the challenges faced by reformers in Peru in particular and more generally by developing democracies.