Wilkins work reads more like a textbook than as an academic text written for other academics. As a result, American Indian Politics and the American Political System at times reads like a survey of Native American political history. For someone who does not have as much knowledge of this history as they feel that they should, this makes for a useful resource, but the text doesn’t carry the intellectual charge as work that more explicitly engages with postcolonial/decolonial theory.
A good overview for those beginning with American Indian politics, the history of federal Indian law, etc. I was given this book back in 2011 when I first began studying American Indians. It serves to spark and interest and briefly begins to explain things to those just entering Federal Indian law--or those that are just curious. I would recommend it for beginners, but eventually you will need to branch out to case specific studies.
The organization of the chapters is a little weird (both the order of the chapters and sections within them), but otherwise a clear and fairly comprehensive overview of a complicated topic.