That odd religious qualification for politics

Why does religion matter for politicians? Most people would consider me religious. I'm one of those people who usually attend a "religious service" two or more times a week. Yet little perplexes me quite as much as the seeming ironclad requirement for a political candidate to be Christian.

If you were to purchase a car, would you rather have the one made or designed by the Buddhist, the agnostic, or the Christian? How about a meal? A wooden cabinet for your living room or a new stereo? How important is the religious affiliation of the person who made what you are about to buy?

Obviously, we don't even consider it. We examine the product instead and make our decision based on the designer or maker's skill - not their religious beliefs. So why does the religion of political candidates matter a whit? Why not focus on their ability to formulate policy, to deal with people?

Yet I have to admit that I'm not completely apathetic about religious affliation. As I get older, I get more uneasy about the idea of religious people being able to start a nuclear war. I think that only atheists should have such power. I don't want the person who could end civilization to have the consolation of an afterlife. I want the guy at the buttons to feel eager to squeeze as many years out of this life as possible.