The outcome of the 2004 presidential election, and the arguments made about religion's role in shaping it, were the subject of tremendous controversy. In seeking to understand how big a factor faith actually played in the Kerry-Bush contest, John Green marshals his considerable experience as arguably America's foremost public religion and politics scholar to provide readers with a thoughtful investigation of the question. The result is a resounding and empirically grounded endorsement of religion's influence in shaping voting among the faithful. However, and as with any broad assessment of political phenomena, there is more to the story than a simple ratification of religious influence on segments of the American public.

Green's central thesis is that what he terms the “old religion gap” — based on historical differences between religious traditions — has given way to a “new religion gap” founded on differences in behavior and belief. More precisely, the new religion gap in many ways exists within the contours of the old religion gap, rendering religious tradition a sometimes-useful framework from which to understand political behavior. Much of the current influence religion has on political behavior, however, is steeped in the “new-religion” alliance between traditional and progressive clusters of believers whose denominational affiliations (to the extent that they exist) vary. While Green is not the first scholar to make this argument, his book is noteworthy for its breadth of treatment of the topic using 2004 exit poll and survey data. Indeed, what the book lacks in originality of argument, it more than makes up for in empirical depth. Readers of all intellectual, religious, and partisan stripes will be delighted with Green's even-handed treatment of complex and impassioned topics. His exclusive use of cross-tabulations to examine relationships in the voter data is an obvious nod to the general reader audience, and the accessibility of the prose matches the statistical approach well.

Part tutorial, part autopsy on the role religion played in shaping the 2004 presidential vote — and continues to play in American politics more generally, the book would be especially appropriate in an undergraduate religion and politics course. It succinctly outlines the general argument for why religion should be treated as a separate, and influential, variable in understanding why voters of different religious backgrounds and degrees of commitment sided with either Kerry or Bush, and Democrats or Republicans more generally. However, and to Green's credit, the argument is not overstated. There is no strident call for religion to supplant party identification as the primary explanation of political behavior among the faithful. Instead, Green gives a solid argument for why religion exerts an independent and unique effect on behavior that is separate from, although sometimes interacted with, gender, age, and income.

One of the more interesting aspects of the book is Green's comparison of religion's influence on presidential voting in 2004 with that of 1944. He uses these years as the basis for comparison of the old and new religion gaps in American politics. Readers will appreciate the historical perspective Green provides concerning changes in the religious and political landscape over these 60 years. However, some readers might wish for a more in-depth treatment of the 1972 presidential election, given the degree to which Green considers this year the beginning of the new religion gap. Indeed, this is the one prevailing weakness of the book. It would have been interesting to see the breakdown of religious voting using 1972 as a watershed between 1944 and 2004.

Readers will find various treats beyond the main text in this volume, including informative chapter notes and an extremely useful appendix that breaks down religious affiliation by state. It is clear that Green wishes the book to be a ready-made resource both in and out of the classroom. His effort provides an important service for educators, scholars, and the general reader looking to situate the role of religion in the study of modern electoral behavior. Written from both a contemporary and historical perspective, the book takes readers through a summary of the “belonging, behaving, and believing” approach to understanding religion's influence on voting — an approach that has made Green and his colleagues staples in the religion and politics literature for decades.

To his credit, Green concludes the volume with an assessment of what his findings likely mean for religion's role in affecting future presidential (and congressional) elections. He presents several scenarios in which the old and new religion gaps play roles of varying consequence. While nothing Green suggests in the last chapter will take readers by surprise, his extrapolation is a fitting way to situate the volume's contribution in the larger literature. In essence, Green has written an empirical desk reference defending the explanatory relevance of religion to American political behavior, at least at the presidential level. Many can learn not only from the book's content, but also the author's ease of explaining complex ideas and synthesizing large amounts of data. The book is truly a contribution to the discipline.