COLUMBIA, S.C. (AP) - South Carolina Education Superintendent Mick Zais is endorsing Sally Atwater to be the Republican nominee in the race to replace him.

Zais said Tuesday he gives Atwater his "strongest endorsement." It comes a week before voters return to the polls for primary runoffs. The widow of GOP strategist Lee Atwater faces Molly Spearman, director of the state Association of School Administrators.

Zais had endorsed Meka Childs, his former deputy superintendent and a former education adviser to Gov. Mark Sanford. Childs placed sixth in the eight-way Republican primary.

Spearman finished first last week, but only by one half of a percentage point over Atwater.

Zais says Atwater will work tirelessly to expand school choice and educator accountability.

The runoff for the Democratic nomination is between Sheila Gallagher and Tom Thompson.