The South Carolina non-presidential primaries are on June 9. The Republican primary ballot will ask an advisory question, “Do you support giving voters the right to register with the Political Party of your choice?” Currently South Carolina has open primaries, and the voter registration form does not ask about party affiliation. Any voter on primary day is free to choose any party’s primary ballot.
If the idea passes with a big margin, in 2021 the Republican Party will probably try to persuade the legislature, which has a Republican majority, to implement a closed primary. Ironically, this year any voter is free to choose the Republican ballot, and this may motivate persons who don’t normally choose the Republican primary ballot to choose it this year.