IN THE EARY 1970s, AT THE HEIGHT OF BRAZIL'S ‘ECONOMIC miracle’, the possibility was mooted by some within the regime of an evolution towards a stable authoritarian system based upon a permanent ruling party capable of governing by consent. The most immediate model in the Latin American context was the ruling Mexican Partido Revolucionario Institucional (Institutionalized Revolutionary Party); hence the term ‘Mexicanization’ to express this concept. However, objective assessments of the prospects were somewhat sceptical. In 1974 President Geisel launched a process of ‘liberalization’, hoping to gain enough popular support through the ruling party, ARENA, to allow a measured relaxation of the repressive controls established after 1964. The process of change thus inaugurated led in little over a decade to the collapse of the regime, and the installation of a civilian, José Sarney, as president in March 1985. As I shall argue below, every move the regime made in its attempt to build a majority party backfired, and, ironically, it was the opposition MDB, whose development was blocked and harassed at every turn, which came nearest to emulating the PRI as a genuinely popular party with cross-class support, a broad national base, and a fund of legitimacy, deriving from its opposition role.