The Tribe asserts that the State Defendants’ efforts to impose personal income tax liability on Tribal members’ per capita payments or casino wages is preempted by federal law and interferes with Tribal sovereignty. The TAC fails to state a claim for relief that is cognizable as a matter of law because, under federal common law, while a tribal member living on her tribe’s reservation is ordinarily exempt from state personal income tax on income earned from on-reservation activities, in this case no Tribal member lives on the Tribe’s reservation. The Tribe’s attempt to explain why its members live off-reservation is irrelevant to a determination whether the exemption applies.