South Carolina has always been an open primary state, since primaries were begun. There is no voter registration by party, and any voter is free to choose any party’s primary ballot.

The South Carolina Republican Party’s ballot for June 12 asks voters who choose the Republican primary ballot, “Do you believe that voters should have the option to choose to affiliate with a political party when they register to vote or change their voter registration in South Carolina?”

The measure is passing with 82%. Here is a link to the election returns. Scroll down to the very end. The voter registration question is Republican Question One. The other Republican question, question two, concerns taxes.