By Chris CasteelStaff writerccasteel@oklahoman.comAttorney General Mike Hunter’s office spent $190,000 for outside legal help this year on a high-stakes question before the U.S. Supreme Court regarding Muscogee (Creek) Nation land in eastern Oklahoma.The state attorney handling the case authorized the payment to the Washington, D.C. firm Arnold & Porter, which has now been paid more than $800,000 by the state for its work on two related cases involving the Creek reservation.Hunter’s solicitor general, Mithun Mansinghani said in a memo provided to The Oklahoman that he negotiated a deeply discounted flat fee for the input of Arnold & Porter on the case that was argued last month before the U.S.