The Oklahoma Democratic Party has formally notified the State Elections Board that independents can vote in its presidential primary and also the primary for other office. See this story. The party actually made this decision on July 25, 2015, but now it is final. This will be the first time any party, other than the Libertarian Party, ever let Oklahoma independents vote in its primaries. The Libertarian Party had done so in 1996 and 2000, although it hasn’t been on the ballot since.

Oklahoma is one of few states that requires all newly-qualifying parties to nominate by primary.