On September 16, the Oklahoma Supreme Court said the proponents of a top-two initiative may begin to circulate their petition. In re Initiative Petition No. 448, State Question No. 836, case no. 123007. Here is the opinion.. It concludes with “The challenge to the proposed ballot title is premature at this stage. We therefore hold that IP 448 is legally sufficient for submission to the People of Oklahoma for their signatures.”

Opponents of the initiative had complained about the use of the term “open primary” to describe the top-two system. “Open primary” has been defined in U.S. Supreme Court opinions and political science textbooks for many decades as a system in which each party has its own primary ballot and its own nominees, but any voter is free to choose any party primary. The initiative is not an “open primary” under the traditional vocabulary. But the Court says that doesn’t matter because the description of the initiative does explain that parties wouldn’t have their own nominees, so the term can be used.

Oklahoma, like most states with the initiative process, has a long tradition that challenges to the constitutionality of a ballot measure should be made after it passes, not before.