Can you spell politics without religion?

In "Politics and Religion Do Mix", Paul Marshall uses examples from history and literature to defend his belief that religion is integral to the world of politics. Though he admits that this political race has been inundated with “God Talk”, he finds the discussion to be not only appropriate but also necessary. In his opinion religion sheds light on topics such as international relations and economic circumstance. We cannot have a true separation of church and state because “religion does not exist in isolation.” It is a part of our every day lives, affecting the way we view everything from our neighbors to our politics.
In order to illustrate the legitimacy of his claim, Marshall calls upon regimes of other world powers, recent historic events, legendary authors, and contemporary research. In the first instance he cites China as an example of an “atheist” country recognizing the importance of religion and pouring money into the development of departments of religion and the study of Christianity at many of its major universities. Next he mentions the current friction between the United States and Muslim fundamentalists, showing how yet again religion is embedded in our policies of international relations. In case current events aren’t your thing, Marshall also includes evidence from Max Weber, Rachel McCLeary and Robert Barro that proves a direct relationship between religious freedom and economic success. According to theses experts there “is more than a mere correlation” between the two, countries with the lowest levels of religious freedom all have “unless they have oil, terrible economic records.”
In his concluding paragraph his message and purpose because shockingly apparent. He declares the importance of religion in not only politics but also economics and discusses the need for more talk about religion from both political parties in a “serious, coherent, and empirically grounded way.”
The only problem I see with Marshall’s argument is that religion in today’s political world, at least when it comes to the presidential campaign, is not talked about it terms of its effect on the economy or neighboring countries. Talk about religion has centered on the individual faith of the candidates. Where is the research that points to the legitimacy of this religious knowledge?