This book addresses two fundamental issues. First, it addresses the current debate regarding the liabilities and merits of presidential government. Does presidentialism make it less likely that democratic governments will be able to manage political conflict, as many prominent scholars have argued recently? Our contribution to this debate is to interject skepticism that presidentialism has generally contributed significantly to the problems of democratic governance and stability, although we recognize that it may have done so in specific cases. These questions about the general desirability of presidentialism have been at the core of a first generation of recent comparative studies of presidentialism that essentially began with Juan Linz's seminal critique of this regime type.

Second, we examine variations among different presidential systems, the implications of these variations for executive–legislative relations, and their consequences for democratic governance and stability. In Chapter 1 and the Conclusion, as well as the nine country chapters, we argue that presidential systems vary in important ways, above all according to (1) the constitutional powers accorded to the president and (2) the kind of parties and party system. We also explore how these variations in presidential powers and the party system affect the performance of presidential democracy. We believe that the first generation of (recent) comparative studies of presidentialism did not always pay sufficient attention to these issues. While we recognize the important contributions of this first generation of comparative studies, we believe that these questions on variations among presidential systems and their implications should form the core of a new generation of studies.