Despite the recent wealth of literature on national populism, research has often overlooked one crucial aspect: the border. This innovative book bridges these key concepts, providing a new theoretical conceptualisation of the interplay between populism, nationalism and territorial borders. In this book, borders are not considered as mere institutional boundaries between nation states; on the contrary, the authors adopt a multi-dimensional view of borders as narratives, issues and territorial spaces of mobilisation. Reconsidering the contemporary politicisation of borders in Western Europe, the authors investigate how national populism deals with territorial borders and the various meanings they embody. Empirical case studies focusing on the Swiss borderlands explore parties' programmes and discourses, representatives' attitudes, as well as public opinion and voting behaviour, offering key insights into how political actors and citizens react to trends such as growing transnational flows, globalisation and European integration. This timely book, based on original party sources and surveys, will be an essential resource for students and scholars of political science, political sociology, border studies, European integration, Euroscepticism and Swiss politics. Its context-oriented analysis will also prove beneficial to practitioners and representatives involved in cross-border cooperation.