On October 1, two voters affiliated with the South Carolina Republican Party filed a lawsuit in state court against the state Republican Party. The party executive committee cancelled the presidential primary on September 7. The lawsuit points out that the state party rules clearly say that only the state convention can make that decision. See this story. Thanks to Political Wire for the link.

UPDATE: the case is Inglis v South Carolina Republican Party, filed in the Richland County Court of Common Pleas, 5th jud. circuit.