The Flandreau Santee Sioux Tribe has opened yet another front against the state of South Dakota in its bid to exert more independence over state government. The tribe filed a lawsuit against the state in federal court challenging the state’s interpretation that contractors working on an expansion of the Royal River Casino are required to pay contractors excise tax to the state. The lawsuit alleges that the state’s imposition of the tax “subjects the tribe to an intrusion into tribal sovereignty within its reservation.” The lawsuit also argues that the state is …