What is the author's tone in God Is Red: A Native View of Religion by Vine Deloria?

The tone used in "God is Red: A Native View of Religion" by Vine Deloria, Jr. switches between objective and partisan. In discussing irrefutable historical fact, Deloria is objective. This tone can also be seen in reference to certain philosophical works and their creators.

The balance of the book exhibits text that is clearly partisan in nature, sometimes to the point of being defensive. It is clear from the outset the Deloria is a member of the Oglala Lakota Sioux tribe and holds fast to the beliefs of his people.