South Carolina's education chief says that up to 25% of the state's public schools could offer single-gender classes by next school year. "We want a choice-driven system here, but one that's accountable," said the state's superintendent of education, Jim Rex, a Democrat who uses a public school-choice model to counter the Republican governor's push for private school vouchers. "We know there are lots of strategies to improve schools, but a lot of them cost money. Let's get real about what's practical now. Single-gender is a strategy that can make a difference now."