Although EU is largely seen as an elite project, the process of enlargement has given mass preferences an increasingly determining institutional role in EU politics. This course aims to provide the students first of all a conceptual framework to analyze the interactions between mass public opinions and international relations. The conceptual framework of two-level games will then be used to analyze the dynamics of public opinions in the enlargement process and the resulting referendums. Basic public opinion analysis techniques will be conveyed to the students and the methodology and main characteristics of the Eurobarometer surveys in member and enlargement countries will be discussed. The interaction between public opinion support for EU membership and Turkish domestic politics will be analyzed in depth with eye towards diagnosing temporal as well lasting impacts of EU membership process on Turkish domestic politics.