immunity and sent the plaintiff to pursue her claim in tribal court. See 436 U.S. at 58-59, 98 S.Ct. 1670; see also Nero v. Cherokee Nation, 892 F.2d 1457, 1461 (10th Cir.1989) (noting the Santa Clara Pueblo distinction between a substantive constraint and an abrogation of sovereign immunity). Absent explicit and unequivocal language to the contrary, the imposition of substantive constraints upon a tribe’s sovereignty cannot be interpreted as an abrogation of its sovereign immunity. We must determine for ourselves whether anything in the Thirteenth Amendment or the 1866 Treaty worked an abrogation of the Cherokee Nation’s sovereign immunity. Again, we will only acknowledge such an abrogation if the text is express and unequivocal. See Santa Clara Pueblo, 436 U.S. at 59, 98 S.Ct. 1670 (<HOLDING>); Fla. Paraplegic, Ass’n v. Miccosukee Tribe,
holding that federal courts lacked jurisdiction to determine whether a tribes membership requirements violated icra and noting that a tribes right to define its own membership for tribal purposes has long been recognized as central to its existence as an independent political community holding the icra not to abrogate tribal sovereign immunity because nothing on the face of title i of the icra purports to subject tribes to the jurisdiction of the federal courts in civil actions for injunctive or declaratory relief holding the copyright act not to abrogate tribal sovereign immunity where nothing on the statutes face could be so construed holding the americans with disabilities act not to abrogate tribal sovereign immunity and declaring congress abrogates tribal immunity only where the definitive language of the statute itself states an intent either to abolish indian tribes common law immunity or to subject tribes to suit under the act holding that removal to federal court does not waive tribal sovereign immunity