on the cases of Argentina and Brazil. It shows that in these two countries the relationships between civil society organizations and
state officials have evolved toward different patterns in terms of degree of conflictivity, the strength and types of ties linking civil
society activists and state officials, and the repertoires of contention adopted. A preliminary conclusion is that, in comparison to
the Argentina case, in Brazil networks of collaboration involving activists outside and inside the state have played a more visible
role. This paper presents hypotheses about these differences between the cases, in an effort to better understand their implications for activism and policy-making. It also seeks to contribute to broader theoretical debates about social movements and their relationship with the institutional
arena.