Nations Under God examines the extent and nature of the political influence of churches on national policy. Its central argument is that rather than influencing policy through electoral politics or the use of public pressure, churches are most influential through backroom politics and institutional access. In fact, churches are most successful at influencing policy when they meet two criteria. The first is appearing to be above politics: “Churches gain their greatest political advantage when they can appear to be above petty politics—exerting their influence through the secret meetings and back rooms of parliament rather than through public pressure and partisanship” (p. 2). The second is that they are considered by politicians and society to have moral authority which, according to Grzymala-Busse, is best gained through a historical record of defending the nation. These factors explain significant variance in success at influencing policies in countries that have otherwise similar patterns of religious belief, belonging, and attendance.

Institutional access is also the most reliable means for influencing policy. Public advocacy, especially when on behalf of narrow church interests, can undermine a church’s moral authority in society. Alliances with political parties can be short lived and these parties can have other priorities. Voters, even in religious countries, do not always agree fully with church views and may vote based on their economic interests rather than their religious views. Thus, if done quietly, the use of institutional access and backroom politics can be the most effective and long lasting means to pursue a church’s political agenda.

This argument is supported by examining three pairs of states in which churches have had different levels of influence, despite the populations of these states being religiously similar. In Chapter 3, Grzymala-Busse argues that despite similarly religious populations, “the Irish Catholic Church has dominated politics and policy far more consistently than its Italian counterpart” (p. 62). This is because in Ireland “the first government’s strong need for the support of a church with great moral authority promoted direct institutional access: parliamentary consultations, policy committees, and personal calls on policy makers. In Italy, the Christian Democratic Party was in dire straits after the war and offered a coalition to a church” (p. 65) which undermined its moral authority (p. 65). Chapter 4 demonstrates that despite similar levels of moral authority at the end of the communist era, the “the Roman Catholic Church has influenced policy in Poland far more than it did in Croatia” because “while in Poland the church relied chiefly on institutional access, in Croatia it was dragged (more or less willingly) into a public and costly coalition with the ruling party,” (p. 145) which undermined its moral authority. In Chapter 5, the book examines the United States and Canada, which have similarly religiously diverse populations; however, these religious groups have had more success in influencing policy in the United States than in Canada. In these cases, religious identities melded and interdenominational coalitions filled roles similar to that of a majority religion and the churches engaged in party politics, but the diffuse nature of the coalitions protected them from erosion of their moral authority. The key difference is that in the United States, religious identity fused with national identity, while in Canada it did not.

The author uses primarily a classic comparative political approach to develop and support her argument, which she supplements with extensive descriptive statistics drawn from surveys and data from other studies. The book’s central arguments are developed in incredible detail. While the theory section is a bit repetitive, the author demonstrates a deep and detailed knowledge of the six cases included in this study. This level of detail is the book’s greatest strength and perhaps also contributes to its most significant limitation—that it does not actively address significant aspects of the larger literature on religion and politics. To be clear, the author addresses the specific literature on the nature of church influence in democracies, contrasting her theory with more classic theories that argue this influence is achieved through public pressure and alliances with political parties. It also addresses in the conclusion chapter the sociological rational thought literature, which argues that religious monopolies lead to less religious populations. In addition, the author shows an awareness of the larger literature on politics and religion and does reference it frequently, but this literature is cited mostly in support of the book’s central arguments with little effort to compare and contrast these arguments with competing and perhaps complementary arguments in the larger literature.

For example, Grzymala-Busse’s theoretical arguments are based to a great extent on the interacting interests of politicians and church leaders. Perhaps the most prominent recent discussion of how the interests of politicians and church leaders interact is Anthony Gill’s book The Political Origins of Religious Liberty, which the book cites but only in passing. The study’s arguments overlap to a great extent with Gill’s arguments and I’d have expected more reference to Gill’s book in the development of these arguments. Yet, Gill has a very different perspective on the issue and the author misses an opportunity to compare and contrast her arguments to his, especially regarding the motivations for entering into various types of church-state relationships. In addition, Gill’s more systematic presentation of the interests of politicians could have been combined with Grzymala-Busse’s more nuanced view of the interests and motives of religious institutions to form a more complete theory.

Similarly the book does not address the normative implications of the study’s findings. How does this theory of church-state relations in democracies relate to notions of the relationship that many argue ought to exist. It seemingly contradicts the arms-length relationship advocated by theorists such as John Rawls and Alfred Stepan. In a related question, what does this real-world relationship say about the role religion plays in democracy on a more general level?

Another limitation of the study is that is focuses exclusively on Christian majority countries in the West, including the former Soviet bloc, four of them Catholic majority countries. Although the book does briefly discuss examples from other countries, most of these examples are Western countries. While there is certainly reason to believe that the arguments in this book are applicable to Christian majority countries in Africa and Latin America, the author missed an opportunity to include cases from these regions, which may have increased the impact of her argument. Similarly, it is possible that this argument has some weight in explaining non-Christian majority democracies, but since the issue is never examined, this remains an open question. In fact the study is even narrower in that in focuses on Church influence on a limited number of issues that are particularly relevant to Western Christian churches: education, divorce, embryonic research technologies, and same-sex marriage.

To be fair, no single book can do everything and despite these shortcomings this book presents an original and insightful argument that is essential to understanding the role of religious institutions in politics. It also sets a research agenda for testing the hypotheses presented in the study in a wider variety of settings.