Since the dual transition to democracy and the market in Latin America, associational linkages or the exchanges between parties and interest associations representing different groups in society gained prominence for their crucial role in structuring political representation and framing policy processes. In the early 21st century, how do the relationships between political parties and interest associations vary across and within countries? The literature on party–voter linkages has begun to examine the distinct relations that emerge when political parties interact with interest associations that represent societal groups in order to incorporate those groups into party organizations or coalitions. Although associational linkages can be constructed when party leaders reach out to interest associations, they can also be constructed when interest associations negotiate the terms of their political support. One approach to analyzing associational linkages involves focusing on the diverse relationships that emerging societal actors established with political parties. Social movements have constructed movement-based parties. These parties are a particularly puzzling phenomenon because they incorporate social movements into their organizations without necessarily demobilizing them. Emerging sectors of organized labor have also established an array of relationships to parties, with unions engaging in contentious or electoral mobilization, with different degrees of support for political parties. There are major opportunities to advance a broad agenda for research on associational linkages that highlights cross-regional contrasts and changes in the political economy.