In 2017, an independent resident of North Carolina, Michael Crowell, filed a federal lawsuit against the law that said only Democrats and Republicans could ever serve on the State Board of Elections, or a county board of elections. The case has been on hold for over a year, because the state policy keeps changing. A new proposal to include one person on the state board who is not a member of either party was passed by the legislature, but then declared unconstitutional on separation of powers grounds.
On October 15, Crowell asked the court to let the case go forward now. He asserts that even if North Carolina ends up allowing a single non-major party member to serve, that is still not constitutionally sufficient. Here is his brief, which has a useful summary of all the action in state court over the makeup of the State Board.