This study seeks to explain variation in the outcomes of cocalero mobilization in Peru and Bolivia. When cocaine became a popular drug in the United States in the late 1970s to early 1980s, governments of the coca-producing countries in the Eastern Andes began implementing policies that included forcible eradication of coca plants, often with U.S. assistance. Cocaleros in Bolivia not only protested against government policy, but also formed a national movement using political alliances that included indigenous and labor unions. In contrast, Peru's cocaleros also mobilized against forced eradication, but a coherent national movement never materialized. This is a problem because social movement literature indicates Peru and Bolivia share many factors that should contribute to increasing levels of mobilization: decentralization measures, a consistent threat from national and international entities, neoliberal reform and backlash, and a recent turn to the political left. This study argues that cocalero movements first require political associational space before they can expand their movement through political alliances and achieve an upward shift in the scale of their movement. Furthermore, it finds that when cocalero movements use credible and resonant frames of protest, they are more likely to mobilize broader support and realize their goals.