The legal precedent established for tribal sovereignty by the ruling in United States v. Cooley (2021) is:
Tribal authority to police extends beyond Indigenous Americans to all U.S. citizens who might be present on tribal land.
This is supported by the excerpt, which indicates that a tribal officer has the authority to detain and search a non-Indian on a public right-of-way that runs through an Indian reservation, thus affirming the tribal police's jurisdiction over non-Indians in this context.