Dr. Oswaldo E. do Amaral is a professor at the Department of Political Science and the director of the Public Opinion Studies Centre (Cesop) at the State University of Campinas (Unicamp), Brazil. He has been a visiting professor at the Universidad de Salamanca (Spain) and visiting researcher at the universities of Oxford (UK) and Notre Dame (US). Between 2013 and 2017, he was co-coordinator of the Research Group on Political Parties and Party Systems of the Latin American Political Science Association (Alacip). He has published several books and articles about the Workers’ Party (PT), the Brazilian party system, party organization, and electoral behaviour.