This book offers a unique perspective of the different experiences of regional integration in Latin America, drawing from theoretically framed case studies on Central America, MERCOSUR, and the Andean Region. It explores new explanations of the widely admitted failure of regional integration in this continent, linking the features of regional institutional arrangements with domestic politics. It also manages both to place the politics of integration in time and to account for the latest development of regionalism following the continent's turn to the left. The book includes an inquiry into regionalism at the hemispherical level, tackling the issue of contentious integration. The type of governance that is building up in the Americas does not seem to be compatible with the pursuit of traditional regional projects and even less with the launching of a new more radical one like the Venezuelan Bolivarian Alternative for the Americas (ALBA).