At its core, regime theory, which is now the dominant paradigm in urban politics, looks at the changing nature of governing coalitions in urban America. Richard Flanagan modifies regime theory by applying Karen Orren and Stephen Skowronek's theory of executive power, which was originally developed to explain presidential politics, to mayors. In particular, Flanagan looks at how temporal factors influence mayoral leadership during regime formation, consolidation, and decay.

Flanagan is interested in the contrast between mayors who exhibit “reconstructive” and “preemptive” leadership. The first group of mayors is successful in replacing vulnerable regimes with new regimes. The second group is able to defeat, but not replace, resilient regimes. Preemptive leaders are forced by the weakness of their electoral coalitions to maneuver in ways that often disappoint their supporters. Consequently, preemptive leaders frequently, but not always, become politically isolated and are often unsuccessful. The author argues that Melvin Holli's list of “best” and “worst” mayors actually distinguishes between reconstructive and preemptive leaders. In other words, political circumstances, rather than personal abilities, are the primary determinant of mayoral success.

Flanagan uses Holli's list of best and worst mayors to identify four reconstructive mayors—Richard J. Daley, David Lawrence, Tom Bradley, and Robert Wagner—and four preemptive mayors—Sam Yorty, Dennis Kucinich, Jane Byrne, and Frank Rizzo. After conducting case studies of each of these eight individuals who occupy the polar extremes of mayoral leadership, Flanagan then examines a more ambiguous set of mayors, preemptive leaders who in spite of their political difficulties successfully implement some political reforms and policy changes. He argues that Fiorello LaGuardia is the best example of a successful preemptive leader. He classifies LaGuardia as a preemptive leader because, for all of LaGuardia's other successes, he was unable to create a new regime to replace the Tammany coalition that had previously governed New York City. Finally, Flanagan examines four modern mayors—Dennis Archer, Ed Rendell, Rudy Giuliani, and Michael Bloomberg—whom he also sees as relatively successful but inherently more conservative practitioners of preemptive leadership. According to Flanagan, each of these mayors managed by emphasizing market-oriented policies and professional management to improve conditions in their cities, even though none of them was able to realign his city's political regime.

Flanagan's case studies are detailed analyses of the shifting political coalitions that supported each of the mayors he examines. Except for the minor error of misidentifying Chicago Councilman William Singer as black (p. 52), the case studies are thoroughly researched and generally accurate. The most valuable are those of the more recent mayors, Archer, Giuliani, Rendell, and Bloomberg, which summarize the careers of mayors who have not as yet been extensively documented. The most controversial part of his analysis is his argument that Fiorello LaGuardia's historical reputation as the nation's best mayor is overrated. Flanagan does a good job of arguing this position, and his conclusion follows when coalition formation is considered to be the acid test of good mayoral leadership. There is more to good leadership, however, than simply coalition formation. The LaGuardia administration successfully managed the economic dislocations caused by the Great Depression, improved the physical infrastructure of New York City, and created a municipal welfare state. The LaGuardia administration is also usually credited with permanently weakening Tammany Hall's hold over the city. By increasing the portion of municipal employees who had civil service protections, depriving Tammany Hall of control over the city for 12 years and disrupting Tammany Hall's connection with the national Democratic administration, LaGuardia so damaged the previous ruling regime as to prevent a return to the status quo ante.

The author's attempt to create a “unified field theory” of executive politics by applying presidential theories to mayoral politics is to be applauded. The three political executives—presidents, governors, and mayors—have a great deal in common. Insights obtained from examining one can fruitfully be applied to explaining the behavior of the others.

Flanagan treats local regimes in much the same way that students of national politics look at party systems. The formation, decline, and ultimate breakup of a majority party system is equated to the formation decline and breakup of an urban regime. National party systems, however, are easier to study. The majority and minority coalitions have formal party labels, and scholars are only interested in electoral results. Urban regimes are harder to measure. The concept of regime includes informal alliances between business interests and political leaders as well as electoral coalitions, and clear labels are often lacking because much of the politics involves intraparty competition and nonpartisan contests.

Nonetheless, explaining mayoral success in terms of the strength and composition of governing coalitions adds a great deal to previous explanations of urban leadership (John Kotter and Paul R. Lawrence, Mayors In Action, 1974; Alan Shank and Ralph Conant, Urban Perspectives, 1975; Douglas Yates, The Ungovernable City, 1977; James Svara, The Official Leadership of the City, 1990) with their overlapping typologies of mayoral activism, which currently dominate the field. Flanagan adds a political dimension to the previous discussions of the causes of mayoral success. The political conditions a mayor encounters are every bit as important as his or her leadership style. The author's approach in conjunction with earlier work provides a more balance view of urban leadership.

There are relatively few comparative studies of mayoral leadership. While historians have written a large number of mayoral biographies and even several city biographies, political scientists have generally not been willing to conduct comparative analyses of big-city leaders. The mayors of major American cities constitute a unique group of political executives who can and should be examined in a comparative manner. The jurisdictions they govern have populations and budgets that are similar to those of a number of states. Their office, no matter how limited its formal powers, is viewed by the public as the personification of local authority. Political scientists need to do more work that examines how the mayors of multiple major cities function. The great virtue of Mayors and the Challenge of Urban Leadership is that it helps to fill this void.