I believe in freedom of religion. I believe politicians can and should vote their consciences and that their consciences should be informed by their faith. I also don't believe that public policy should be formed around religious preferences. That basically means that when a politician puts forward a policy that is consonant with their faith, they better also have some good reasons that are outside of their faith. A foundation in one's faith is not enough to form public policy.
I respect politicians who truly hold their faith, whatever it may be, and live it with authenticity. I have no respect for politicians who use faith as a wedge between constituencies and I have little respect for politicians who are less than genuine in their commitments.
That brings me to Rick Santorum and Newt Gingrich, both of who have been playing the "good Roman Catholic" card of late. Neither is a good Roman Catholic. Both are ignoring the nature of authority in the Catholic church. They think and act as if a good Roman Catholic can pick and choose between the teachings of the church and embrace those that fit their own politics or morals while rejecting others. While in fact, many who call themselves Roman Catholics in the US do just that, it is a difficult place to be when the Catholic Church is built on a hierarchy of authority which cannot be easily ignored. Juan Cole has an interesting blog piece entitled the Top Ten Roman Catholic Teaching Rick Santorum Rejects While Obsessing about Birth Control where he shows how Santorum does just that. These two politicians claim to be pro-life and point to their supposed Roman Catholic faith as the foundation for that understanding, all the while ignoring that in Roman Catholic teaching, pro-life is a much broader term that rejects capital punishment, any kind of pre-emptive war, most specific wars including Iraq, and which calls for universal health care, welfare for all needy families...
The first time a politician stands up and says "I am against birth control because I'm a Roman Catholic... and I'm also against capital punishment. I take Just War Theory seriously and I believe in a safety net that truly provides for the needs and dignity of the poor," I will take that person seriously. Until then, he or she can't say that they hold a position based on the authority of their church without me laughing at them. I laugh at Santorum and Gingrich.
Now, there are other kinds of Christians who understand authority very differently. The Baptist tradition, for example, says that an individual's relationship to God is between them and God. Authority does not come from a hierarchy but from responsible reflection by the individual and interaction with the Holy. Without responsible reflection and without relationship to the Holy, there is no authority. Even when the relationship is authentic, in this tradition, one still cannot generalize the shape or substance of another's relationship with the Holy. (This is why freedom of religion was an idea that came primarily from the early Baptists). I know many in this tradition, my tradition, who see things very differently than I do. Some I respect deeply because their views are based in responsible reflection and in their understanding of their relationships with God. Others... not so much.
Still other traditions place the authority in the gathered community. The bottom line is that if one is going to claim religious authority for a particular stand, they had better understand how authority works in that tradition and own the tradition.