Article 1, Section 8 of the Constitution of the United States vests the federal government with the authority to engage in relations with the tribes, and thereby, firmly places tribes in the Constitutional family of our nation. Tribes possess all powers of government, except those, which Congress has expressly extinguished or which the Supreme Court has ruled are inconsistent with overriding national interests.
Tribes have the inherent right to operate under their own governmental systems.
Many have adopted constitutions, while others operate under Articles of Association or other bodies of law, and some still have traditional systems of government. The chief executive of a tribe is generally called the tribal chairperson, but may also be called principal chief, governor, or president. The chief executive usually presides over what is typically called the tribal council. The tribal council performs the legislative function for the tribe, although some tribes require a referendum of the membership to enact laws. A federally recognized tribe is one that was in existence, or evolved as a successor to a tribe at the time of original contact with non-Indians.