CHARLESTON, S.C. — A runoff will be needed to determine a Republican candidate for a vacant South Carolina House seat.

Unofficial returns from Tuesday’s primary show Daniel Island businesswoman Nancy Mace and former Mount Pleasant Town Councilman Mark Smith will meet in a runoff Nov. 28.

The seat was vacated when Rep. Jim Merrill resigned shortly before he pleaded guilty in an investigation of Statehouse corruption. The district covers parts of Charleston and Berkeley counties.

Mace got about 49 percent of the vote Tuesday, Smith had about 27 percent. State law requires a candidate to receive a majority of the votes to be elected.

Mace was the first female cadet to graduate from The Citadel, in 1999.

The winner of the runoff will face Democrat Cindy Boatwright in a special election Jan. 16.