I think part of the reason for that is because of the Reformed / Calvinistic world-view that seems to dominate in many areas, which says that 'nothing happens unless it's God's will'. I've written a little bit about that on my other blog.
Here are a couple of paragraphs from the article linked above, just to give you an idea what it's about:
Yet, as a whole, the church responded by promoting political involvement as the answer to society’s woes. Make no mistake—Christians who live in a country that provides them the freedom to govern through voting or holding political office have a responsibility to participate. However, for many, politics has not been a weapon against the moral decline; it has been the only weapon.And
Our society isn’t sick because of the government; it’s sick because the church has not made faith in the teaching of the Bible “practically universal in our country.” Once we cease to win the hearts of man, it is inevitable that ungodly people will make their way into leadership and take the country with them.I somewhat disagree with the contention that the Government does nothing to form people's beliefs. I believe there is a faction that has done their level best to get their agenda into the public schools, which goes a long way to helping people form their beliefs. Not to mention government influence on the media, and vice versa.If we change people’s hearts with the Gospel, the people will change the government with their votes. Government merely reflects what people believe in their hearts; it does nothing to form those beliefs. William Penn, the founder of Pennsylvania, wrote in the late 1600s, “Government seems to me to be a part of religion itself…. Let men be good, and the government cannot be bad.”
Overall I think it's a very good article, with a good amount of historical quotes added to give context.
