This paper studies party system responsiveness in Latin America, which displays a wide variation in the degree to which parties are anchored in society and reflect specific social groups. The first task is to discuss how congruence between voter preferences and party positions should be measured, which involves not only a number of methodological and conceptual issues, but also questions ultimately rooted in differing normative conceptions of representation. I then move on to assessing empirically what constitutes the relevant dimensions of conflict in ten Latin American countries, and measure the quality of representation along these dimensions. My expectation is that congruence in the first rounds of elections in new democracies depends chiefly on the presence of historical cleavages from prior democratic experiences. The earliest point in time for which data from the Survey of Latin American Legislators (PELA) can be matched with public opinion data to test this hypothesis is the mid-1990s, reasonably close to the transition to democracy that many countries experienced in the 1980s. In a second step, I assess congruence ten years later, and analyze the determinants of change. While I expect stability in those countries where parties already mirrored voter preferences reasonably well before, the subsequent dynamics in less institutionalized party systems are more contingent, and more strongly depend on the agency of political actors. Specifically, I test the hypothesis that outsider parties with a clear ideological profile are able to force their opponents to rally around a common set of policy positions as well. Supposedly, if voters are presented clear options, this is conductive to establishing mechanisms of accountability between parties and voters. Cases expected to conform to this pattern are Brazil during the rise of the Workers’ Party, as well as Mexico during the PAN’s challenge to the once-dominant PRI.
