This book focuses on two linked questions. Firstly, what impact has Poland had upon the EU as a new member state? Secondly, how has becoming an EU member impacted upon public attitudes towards the EU and Polish domestic politics, particularly on its party and electoral politics? Szczerbiak provides the first detailed empirical case study of the impact of Poland’s EU membership on its politics and of Poland's impact on the EU. The book also makes broader theoretical contributions to our understanding of EU relations with its member states. As a result of the above, this book will be of interest to students and scholars of European Politics, political science and European integration.