This book explores the question of why and under which conditions right-wing populist parties receive electoral support. The author argues that neither economic variables, nor national culture or history are what account for their successes. Instead, he illustrates that the electoral success of populist parties in Western Europe, such as the French Front National or the Alternative for Germany, is best understood as the unintended consequence of misleading political messaging on the part of established political actors. A two-level theory explains why moderate politicians have changed their approaches to political messaging, potentially benefiting the nationalist, anti-elitist and anti-immigration rhetoric of their populist contenders. Lastly, the book’s theoretical assumptions are empirically validated by case studies on the immigration societies of Germany, the Netherlands and Sweden.