I suppose it just makes for simpler story telling on their part and there are enough people who fit that mold that it is true to some limited extent.
But in my years of experience of talking with people of religious faith there is quite a bit of diversity of views on politics.
Just a few examples:
One person I knew was a fiscal conservative and socially liberal with the view that the government isn't in the business of morality.
Another friend is pro-life but doesn't have any strong feelings about economic matters.
A third example is a pro-lifer who is against the death penalty and usually votes democrat.
Then there is good friend who is pro-life but libertarian in economics and most other social issues.
And indeed, I have friends who are down the line conservative: pro-life, fiscal conservatives, in favor of the death penalty and will vote Republican no matter w…