Tribal Sovereignty: the place to start, place to continue
Sovereignty can be defined as the inherent and supreme power from which a people derive their social, political and economic governance. It is the basis upon which a nation is formed and a people govern themselves. Sovereignty is established and asserted by the will of the people, and not ultimately contingent upon some other nation granting it to that people. Indian tribes were sovereign nations long before Columbus set foot on the shores of "his new world," and long before Lewis and Clark exchanged "peace medals" with the tribes of the disputed Oregon Country (as England also claimed this area). Indian sovereignty must ultimately be defined, affirmed and asserted by Indians themselves. Nevertheless, how the U.S. government defines its relationship with the Tribes directly affects tribal sovereignty today. This history has been as if a pendulum, swinging between self-determination and dependency.
While the United State federal government may seek to use this language and assert the power of these words (e.g., "plenary" or "domestic, dependent nation"), it is ultimately up to each Indian Nation to decide on the degree they wish to bow to the power of these words, or assert their own definition of sovereignty.
Bush, McCain and Obama on Tribal Sovereignty (on the difficulty in defining Tribal Sovereignty)