The contemporary electoral process is in many ways far more complex than it used to be. This book focuses on the growing involvement of non-party actors in the process of selecting candidates and during the campaign itself. These actors – interest groups, individual citizens, even certain political institutions – operate in the campaign environment independently of the parties and their candidates. They are not seeking to attain public offi ce; nevertheless, they interfere in the electoral process in growing numbers, and with increasing intensity, for the most part seeking to infl uence electoral outcomes to their advantage, but on occasions also for less selfi sh reasons, such as increasing the quality of the electoral process itself. Encompassing a broad range of countries, including several old democracies (the United States, Germany, Britain, Norway, Denmark, Belgium, Israel, and others), but also one new democracy (Romania), and combining extensive surveys with detailed case studies of recent elections, the chapters in this volume take stock of this new feature in the contemporary electoral process, its origins, forms, and consequences.