There was a good article, "A religious test all our political candidates should take", in last Sunday's Washington Post about, essentially, religious bias or the potential for it in politics. The article noted that John F. Kennedy's famous speech about his Catholicism helped to push the view that a person's religious beliefs are politically irrelevant. However, this notion of religion being a private matter changed at some point. Politicians in the US, it's very atypical elsewhere, I believe, wear their religion on their sleeve and we've come to expect candidates for office to give us some sort of "testimony". An atheist would be very unlikely to gain office in the US, so the US electorate expects politicians to embrace a traditional, from a US perspective, religion and politicians like to use their religion to gain political points.
The article contends that while it may be tempting to go back to relegating religion to the private sector, that that may not be prudent. As a matter of fact, one's religion has profound implications for one's views on morality, the government's role in enforcing it, and authority. So, rather than letting the candidates simply make pietistic feel good statements about his/her religion, we need to be asking candidates how they would resolve possible tensions between the dictates of their religion and their church and their rights and responsibilities as leaders.
I would add, and perhaps it's implicitly stated in the article, religion has the further potential to have profound implications on a person's views of ontology and epistemology as well. In fact, if a person is serious about his/her religion it will have a profound effect on their actions in the political realms even when there is no explicit conflict between church dogma and legislation. For example, one's views on the acceptability, or non-acceptability, of divine revelation as a legitimate means of coming to have knowledge might affect one's views on the breadth of the school curriculum. One's interpretations of Christ's demands to love one's enemies might affect one's perspective on foreign policy and willingness to launch attacks. Or the flip side might be that one's views that all non-Christians (non-Muslims), are doomed to hell and/or that this life is nothing but a painful precursor to an eternity of bliss may also affect one's willingness to attack another nation. One's views that Christ's return to earth is imminent might affect one's willingness to implement long term environmental policy requiring short term pain. If one's religion postulates a lower role or traditional role for women, one might be less likely to pursue Equality in the Workplace legislation. So, not only should we concern ourselves about explicit points of conflict but we should also try to understand how religion might affect the politician's entire worldview and the policies s/he might enforce.
Religious convictions are convictions on matters that are of fundamental importance. (In fact, I'd contend that we all hold religious beliefs of some sort, insofar as assumptions, even working assumptions, about the nature of humankind, whether we're alone in the universe, whether there's a higher power, legitimate means of coming to knowledge, on the sorts of things that exist, are all, in some sense religious beliefs, insofar as they're profoundly important and usually embraced with a measure of faith. ) In America, however, we've sort of come to the worst of all possible worlds. We don't ignore religion in political discourse, but we allow it to operate only at the level of platitudes. As the article suggests, if religion really means something , let's ask hard questions about what it means. These fundamental convictions may very well mean something important and candidates owe us an account of what they think they mean when the rubber hits the road. Now, I also think that for very many politicians religion isn't operating at a profound metaphysical level, their religious practice is more or less a social activity and/or a comforting set of rites and rituals. Nonetheless, if that's the only role it's serving, candidates should be clear about that.