To what extent do party labels influence individuals' policy positions? Much research has examined this question in the United States, where party identification can generate both in-group and out-group pressures to conform to a party's position. However, relatively little research has considered the question's comparative generalizability. We explore the impact of party labels on attitudes in Brazil, a relatively new democracy with a fragmented party system. In such an environment, do parties function as in-groups, out-groups, or neither? We answer this question through two survey experiments, one conducted on a nationally representative sample and another on a convenience sample recruited via Facebook. We find that both in-and out-group cues shape the opinions of identifiers of Brazil's two main parties but that cues have no effect on nonpartisans. Results suggest that party identification can structure attitudes and behavior even in "party-averse" electoral environments. P artisanship is a core heuristic individuals use to make sense of politics. It shapes voters' opinions on a range of issues, motivates engagement in politics, and impacts vote choice. Most of what we know about the nature and impact of party identification (ID) comes from the United States, where the same two parties have competed for over 150 years, and where scholars have found ample support for the idea that source cues can shape public opinion (Goren, Federico, and Kittilson 2009;Greene, Palmquist, and Schickler 2002;Lau and Redlawsk 2006;Sniderman, Brody, and Tetlock 1991).Over the last 30 years, new democracies have emerged in nearly every corner of the globe. Scholars have increasingly turned their attention to the study of voting behavior in these countries. However, relatively little experimental research has considered whether the core concept of mass partisanship can travel into such different political contexts, particularly where political parties are new and numerous (for an exception, see Barder and Tucker 2012). Miller, and to the anonymous reviewers and editors at AJPS for comments and suggestions. Thanks to Ted Brader for sharing ideas and experiences with partisan cueing experiments. The online surveys were approved by the IRBs of the University of Minnesota (#1110S05602) and Rutgers University (#E12-231). Thanks to Andy Sell in the University of Minnesota's College of Liberal Arts Office of Information Technology for helping implement and manage the online survey. because free and fair elections are a relatively new phenomenon, and as such, partisanship has had less time to develop as predicted-as a function of consistent information parties provide to voters (Fiorina 1981). Moreover, although individuals in established democracies partly inherit their partisan disposition from their parents (Converse 1969;Jennings, Stoker, and Bowers 2009), in new democracies, neither older nor younger citizens have had many opportunities to vote-and in any case the political context may have changed dramatically and rapidly in recent yea...