Author(s) Charles K.S. Wu Keywords public opinion, social movements, cross-Strait relations Abstract The 2014 Sunflower Movement succeeded in blocking Taiwan’s Congress from ratifying the Cross-Strait Services Trade Agreement (CSSTA), a bill that proposed to liberalize trade with China. Since most of the participants in this movement were students and NGO members, they had limited economic and political resources to influence policy change, which makes their success in stopping a trade deal remarkable. Many attribute this important success to an elite alliance with politicians inside the government, fueled by a personal rivalry between political elites. However, I argue that changing public opinion is the more important force behind the creation of the alliance. With original data from interviews with political elites, their staff members, and activists in Taiwan, in addition to secondary information, I confirm public opinion to be the major reason for the political alliance. This case illustrates that in some circumstances, public opinion outweighs the importance of elite rivalry in influencing political elite decision-making, and it could represent a key mechanism of democratic policy-making. DOI: https://doi.org/10.1017/jea.2019.30 Author(s) Bio Charles K.S. Wu (wu721@purdue.edu) is a doctoral student in the Department of Political Science at Purdue University