摘要：The regular growth of effective number of parties has been a major issue to the proper working of Brazilian political system. Still, little has been said regarding how the competitive interaction among political parties has an effect on the social composition of its candidates and elected. Trying to stablish relation between party strength, social composition and party system fragmentation, we put our efforts on checking how system fragmentation undermine strong parties in giving room for socially less competitive candidacies. In our hypothesis, we affirm: as higher the party organizational strength, bigger is the capacity of electing an outsider social group into representative arena, such as workers. Data points out that Brazilian Workers Party (pt) is the most organizationally structured party. However, through five consecutive elections, pt loses capacity to put in place organizational strength in favor of workers, diminishing its capacity to push forward blue- and white-collar workers into institutional polity. We show of that part of the loss is due to the increasing party system fragmentation from 1998 to 2014.
