I blogged earlier about a challenge to Missouri's participation in "Common Core," an education system developed in part by encouragement from the United States Department of Education. The challenge alleged that the standards violated the Compact Clause, because it effectively undermined federal power and the power of non-compacting sister states, and it had not been approved by Congress. (I've written about the need for congressional consent of interstate compacts before.)

Yesterday, a state court issued a temporary restraining order prohibiting Missouri from making payments to the education consortium administering Common Core on the ground that plaintiffs made a preliminary showing of likelihood of success on the merits: "For the reasons stated in the Plaintiffs’ Memorandum in Support of their Motion for Preliminary Injunction, Plaintiffs have made a preliminary showing of likelihood of success on the merits on their claim that the Consortium is an unconstitutional interstate compact to which Congress has never consented, in violation of the Compact Clause of the U.S. Constitution. If Plaintiffs prevail on this claim, Missouri’s membership in the Consortium is unconstitutional." A copy of the TRO is here.