South carolina constitution
Article III: legislative department
Section 7

No person is eligible for a seat in the Senate or House of Representatives who, at the time of his election, is not a duly qualified elector under this Constitution in the district in which he may be chosen. Senators must be at least twenty-five and Representatives at least twenty-one years of age. A candidate for the Senate or House of Representatives must be a legal resident of the district in which he is a candidate at the time he files for the office. No person who has been convicted of a felony under state or federal law or convicted of tampering with a voting machine, fraudulent registration or voting, bribery at elections, procuring or offering to procure votes by bribery, voting more than once at elections, impersonating a voter, or swearing falsely at elections/taking oath in another's name, or who has pled guilty or nolo contendere to these offenses, is eligible to serve as a member of the Senate or the House of Representatives. However, notwithstanding any other provision of this Constitution, this prohibition does not apply to a person who has been pardoned under state or federal law or to a person who files for public office fifteen years or more after the completion date of service of the sentence, including probation and parole time, nor shall any person, serving in office prior to the ratification of this provision, be required to vacate the office to which he is elected.