Final answer:
The claim that exclusive governmental power in American Indian country lies solely with tribal governments, denying any power to federal and state governments, is false. While tribes have significant self-governing authority, the federal government can enact laws that affect them, and states have certain limited powers, especially around negotiated compacts such as gaming.
Step-by-step explanation:
The statement that the exclusive governmental power to make or enforce laws in American Indian country is completely in the hands of tribal governments; federal and state governments have no power in Indian country is False. While it is true that American Indian tribes, considered "nations within a nation," have substantial sovereignty and can self-govern with powers to tax, legislate, and judge, this power is not exclusive or absolute. The federal government, through Congress, holds the power to pass laws that apply to Indian tribes and their members, though it generally strives to respect tribal sovereignty. States typically have limited power in Indian country; however, cases where tribes have compacted with states, such as with the Indian Gaming Regulatory Act, do exist. Furthermore, historical legislation and court decisions have shaped and sometimes reduced tribal sovereignty and self-governance, indicating a complex balance of authority between tribes, the federal government, and states.