This is so DGH, it’s not worth trying to Guess Who:
An implicit assumption of faith-based politics is that people who hold the same religious convictions will, or at least should, look at the political order in similar ways. Some invoke the idea of worldview. Faith creates an outlook that prompts believers to see the world in a specific way, one that calls for similar forms of political engagement or similar kinds of policy and legislation. This assumption has been crucial to Republicans’ cultivation of evangelicals. Born-again values voters share a perspective that will rally around certain proposals or ideals.
A moment’s reflection reveals the folly of such an assumption. Evangelical Protestants are one of the least unified groups of American believers at the level of ecclesiastical affiliation and religious organization. Enough differences exist between Wesleyans and Calvinists, Baptists and Pentecostals, megachurches and small congregations to prompt a veritable cornucopia of fellowships and associations. (One could make a similar point about Roman Catholics and Jews; neither of these groups in the United States has yielded predictable uniformity.) Why then would pundits and scholars treat evangelicals as if their faith, which on Sundays divides them along a host of theological and institutional lines, would unite them when they line up on the first Tuesday in November to cast their ballots in presidential contests?
From Billy Graham to Sarah Palin: Evangelicals and the Betrayal of American Conservatism, p. 145.