The main thesis of this book is that conventional approaches to the study of parties have driven agency out of the analysis of their subject. This applies to both political sociology, treating parties as the epiphenomenal reflection of social categories, and the rational choice spatial-competition theory, conceiving party strategies as logically compelling functions of politicians' office-seeking quests, constrained by the structure of demand and supply in party competition. Agency involves a collective level—party organizational structure—and an individual level, the conduct and choices of politicians. The critical question, then, concerns the extent to which parties' organizational structures and—in part via incentives conditioned by these—the actors' strategic choices operating within parties may produce party conduct the nature of which diverges from what the purely sociological or spatial-systemic theories would predict.

Alan Ware plans to demonstrate this conduct with regard to three critical phenomena in the trajectory of major parties in two-party systems: 1) their collapse and loss of major party status, 2) their survival as small parties or their dissolution, and 3) party efforts to maintain or acquire major party status through mergers with minor parties. In a purely sociological world, or a rational world of equilibrium strategies, none of these outcomes would occur: Major parties would always be able to optimize their survival (in the rational world) or parties' success would entirely depend on changes in the social structure that alters the relative strength of each party (in the sociological world). But in the real world of politics, party organization and actors manage a party's environment and may bring about party decline and resurgence. Such phenomena are the objects of the book's investigation.

Ware intends to demonstrate the relevance of these processes by examining two-party systems, defined as polities in which most of the time 1) single parties govern and 2) the governing party controls the legislative majority. He restricts his attention to two-partism because it permits a simplification of the parties' goal functions: Maximizing support and being pivotal for government formation is the same thing, whereas in a multiparty system, one may conflict with the other (p. 20). This should make it easier to identify where structure and action make a difference beyond partisan sociology and systemic imperatives of competition.

The critical mechanisms beyond sociological determinism and rational choice strategic equilibria that affect parties' fortunes are 1) a loss of a party's role as “focal arbiter” (Thomas C. Schelling, The Strategy of Conflict, 1960), 2) a collapse of a large party's resource advantage and, most importantly, 3) entanglement of a party in confronting two adversaries on different fronts simultaneously. In the empirical, comparative case study chapters of the book, Ware then details how different causal mechanisms affect different watersheds in the development of parties in two-party systems. First, the loss of major party status is driven mostly by a party's having to compete on two fronts against new competitors that overload a focal party's capacity for strategic response and ultimately make it lose its role as focal arbiter and its capacity to mobilize resources. The author demonstrates this development for the Canadian Progressive Conservatives before 1993 (with different challenging parties in the western Canadian provinces and in Quebec), the American Whigs 1852–56 (Know Nothings and Republicans as challengers), and the British Liberals after 1916, although in this latter case, the “fight on two fronts” acquires a new meaning: Rather than coping with two different opponents, the Liberals fought only one opponent/ally (the emerging Labour Party), but on two strategic dimensions, concerning how far to go with policy concessions to the labor ally and how many districts to concede to the emerging ally's exclusive fielding of competitors against the Conservatives.

The question of the survival of a party's label, once a party loses its major party status, in turn, depends more on the organizational structure of the party. In a comparison of the collapse of the U.S. Whigs in the 1850s and the British Liberals from 1916 to the 1930s, Ware argues that ultimately the centralized, interconnected nature of party organization and office seeking across different levels of government in the United States, in combination with the spoils system, made ambitious politicians quickly defect from the Whig party once it lost its focal arbiter status, thus precipitating the sudden collapse and disappearance of the party. By contrast, the less nationally integrated, homogeneous, and stratified character of the UK Liberals made it possible for politicians with rather different ambitions and aspirations to uphold the partisan label, even once the national Liberals had irreversibly lost their bid to constitute one of the two major British party alternatives contesting national-governmental executive office.

Finally, the capacity of major parties to remain hegemonic or of minor parties in a dominant two-party system to aspire to major party status (again) depends more on political agency—the skilled leadership of individual political actors in engineering party fusions—than on resource endowments, organizational capacities, or two-front competitive configurations. Ware invokes William H. Riker's work on heresthetics (The Art of Political Manipulation, 1986) as critical for the achievements of fusion among parties. Across two chapters (5 and 6), he spells out hypothetical and actual considerations that may enter politicians' strategies toward different kinds of party fusions, accompanied with copious examples from a wide range of the nine two-party system polities identified among democracies. The treatment of this subject, however, has a rather more diffuse and inductive feel than the argument developed in other chapters about the permanent and irreversible decline of major parties in two-party systems.

Ware's basic point that party structures and political agency matter is well taken, and the book invokes a great deal of case study evidence to illustrate the point. But the theoretical conceptualization of these complements—or alternatives?—to sociological and formal rational choice spatial-party-competition theory could have been pushed further analytically in conversation with the existing literature. On the one hand, the formal party competition literature itself—from Anthony Downs's Economic Theory of Democracy (1957) to Gary Cox's Making Votes Count (1997) and James Adams, Samuel Merrill, and Bernard Grofman's Unified Theory of Party Competition (2005)—helps to clarify the limits of purely systemic arguments to derive equilibrium strategies for parties when applied to the empirical world. It indicates a host of premises that are critical for maintaining two-party-system equilibria or guaranteeing the survival of any particular major party within such systems. By implication, violation of these criteria may empirically account for the failure of parties to maintain their major party status. On the other hand, there is indeed a rather large theoretical and empirical literature on the role of party organization—the relationship between activists and party leaderships, or more generally, the interplay between the extensiveness of party organization/membership and the centralization of intraparty control over politicians' career advancement and leverage over parties' strategic choices in interaction with other parties—that Ware does not draw upon or engage in order to sharpen his hypotheses and analysis of party demise and termination in two-party systems.

Finally, let me make a rather plain, methodology textbook–based criticism of the book's research design. Ware's analysis relies only on cases of actual major party decline and collapse in two-party systems. This smacks a bit of sampling on the dependent variable. It would be better to show in exemplary fashion that in other times and places, two-party systems survived intact precisely because the critical variables Ware brings into play in the cases of party decline are, in fact, absent. In this regard, it might have helped had he drawn more systematically on all nine polities that he identifies as having two-party systems, rather than primarily on the British, Canadian, and U.S. experiences.

In spite of these limitations, Ware's study constitutes a critical corrective and analytical complement to the existing literature on party competition. Anyone dissatisfied with purely sociological approaches to partisan politics or formal deductions of party equilibrium strategies should turn to this treatment of the subject of party competition and its consequences in two-party dominated polities.