Why does religion play such a huge role in American politics when America is such a religiously diverse nation?

We have Christians. And they do not always agree with each other on certain tenets of faith (i.e. Catholics and protosenants do not agree on certain things, Mormons follow their own version of Christianity that includes the Book of Mormon and practices not performed by other denominations, there are liberal Christians and Christians that are so conservative that they live like it's the 17th century- Amish, and so on). We have Jews (of different styles of worship). We have Muslims. We have Hindus. We have Wiccans and naturalists. We have various Native American beliefs that are observed by some American Indians. We have atheists. And the list goes on and on. So, why is religion even allowed at the table of politics?