S.C. Code § 7-17-590
The State executive committee of every political party in this State which may have such a committee shall immediately after its appointment elect from its body a committee of one from each congressional district which shall constitute the Board of State Canvassers for Municipal Primaries, each of whom, before hearing any appeal, shall take and subscribe an oath that he will fairly, impartially and honestly decide such an appeal. The board shall, upon collection by their chairman of the estimated amount of the expenses of such appeal from the person or persons making it, decide as judicial officers all cases under protest or contest that may come before them on appeal from any decision of such committees or canvassing officers from whose decisions appeal is made upon the papers transmitted to them by such committees or canvassing officers, and the person or persons declared by the board to be nominated at such election shall be the nominee or nominees of such political party in the respective elections for which such nominations were made. Any vacancies in said board shall be filled by the State executive committee or, in case it should not be in session, by the chairman of the State executive committee. The members of said board shall serve until the meeting of the next State executive committee. A majority of the members of the board shall constitute a quorum at any meeting.
S.C. Code § 7-17-590