It is well established that “Indian tribes are domestic dependent nations that exercise inherent sovereign authority. Oklahoma Tax Commission v. Citizen Band Potawatomi Indian Tribe, 498 U.S. 505, 509, 111 S.Ct. 905, 112 L.Ed.2d 1112 (1991); Michigan v. Bay Mills Indian Community,_ U.S._, 134 S.Ct. 2024, 2030, 188 L.Ed.2d 1071 (2014). “Among the core aspects of sovereignty that tribes possess – subject, again, to congressional action – is the common-law immunity from suit traditionally enjoyed by sovereign powers …. That immunity, we have explained, is a necessary corollary to Indian sovereignty and selfgovernance.” Three Affiliated Tribes of Fort Berthold Reservation v. Wold Engineering, P.C., 476 U.S. 877, 890, 106 S.Ct. 2305, 90 L.Ed.2d 881 (1986).
In Michigan v. Bay Mills Indian Cmty., supra, this Court explained that the “baseline position … is tribal immunity; and [t]o abrogate [such] immunity, Congress must unequivocally express that purpose …. That rule of construction reflects an enduring principle of Indian law: Although Congress has plenary authority over tribes, courts will not lightly assume that Congress in fact intends to undermine Indian selfgovernment.” (Citations omitted; internal quotation marks omitted.) Id., 134 S.Ct. at 2031-32.
Lower court materials here.