Theories about the decline of legitimacy or a legitimacy crisis are as old as democracy itself. Yet, representative democracy still exists, and the empirical evidence for a secular decline of political support in established democracies is limited, questionable, or absent. This lack of conclusive evidence calls into question existing explanatory theories of legitimacy decline. How valid are theories of modernization, globalization, media malaise, social capital, and party decline, if the predicted outcome (i.e. secular decline of political support) does not occur? And which (new) explanations...