South Carolina’s highest-profile Democrat, Inez Tenenbaum, Friday challenged Republican Gov. Mark Sanford to rein in a private group airing ads critical of the state’s public schools.

The move by Tenenbaum, the state’s education superintendent, is the latest skirmish in an increasingly heated battle over Sanford’s proposal to give tax breaks to parents who want to send their children to private school or another public school.

The pro-tax-credit ads, which use Tenenbaum’s voice, “cross the line,” she said. The tax credit bill, she said, would be bad for the state.

The ad uses a clip of Tenenbaum saying, “We have accomplished so much,” followed by an announcer, countering, “The truth is far different.”

According to the ad, South Carolina’s students perform below the rest of the country, and the state’s drop-out rate and test scores are the worst in the nation.

Tenenbaum denounced the ad’s tone, saying it ignores the progress S.C. students have made.

“It’s one thing to use attack ads to ridicule a political candidate,” Tenenbaum said. “It’s another thing to criticize schools and schoolchildren.

“As the governor of this state, (Sanford) should start being an advocate for public education and stand with me.”

Denver Merrill, spokesman for South Carolinians for Responsible Government, the private group that paid for the ad and back’s Sanford’s tax credit bill, said it is an answer to an S.C. Education Association ad, which mimics Sanford.

Those ads say Sanford’s plan — now in the S.C. House — would take hundreds of millions of dollars from schools while helping just a few taxpayers.

Sanford won’t tell South Carolinians for Responsible Government to cancel the ad, spokesman Chris Drummond said, pointing out that Tenenbaum didn’t ask for the SCEA to cancel theirs.

Sanford does not support either ad, he said. “It’s unfortunate the conversation we’re having now is about ads rather than about issues like improving education in our state.”

Jim Foster, Tenenbaum’s spokesman, said the difference is that the SCEA ad “was clearly a parody.”

Sanford’s tax credit bill, dubbed “Put Parents in Charge,” has divided the Legislature.

Supporters say the tax credits would force public schools to compete and improve.

Opponents — Democrats and some Republicans — worry it would drain resources from public schools and other state-funded programs.

Advocates on both sides have used campaign-style techniques to push their positions.

But Sen. Joel Lourie, D-Richland, a tax-credit opponent, said South Carolinians for Responsible Government has used “cheap tricks,” including the radio ad and direct mail.

He agreed that Sanford should take a stand and ask South Carolinians for Responsible Government to stop their ads.

Merrill said Tenenbaum and other bill opponents are using scare tactics to distract from the truth. “She sounds like a broken record. If she would come up with a new verse, we would be willing to incorporate it into our ads.”

At a news conference Friday, Tenenbaum said South Carolinians for Responsible Government cherry-picked rankings that make S.C. students look bad.

Tenenbaum acknowledges that too few S.C. students graduate high school in four years. She took exception to the ad, which said the drop-out rate is the worst in the country. Federal data puts S.C. closer to the middle of the pack, she said.

While South Carolina’s SAT scores are 50th in the nation, she said, its students rank in the middle in other standardized tests.

Merrill said South Carolinians for Responsible Government stands by its ad. “We’re last in SATs, we’re 49th in ACTs. Those are the statistics people need to understand.”

Reach Talhelm at (803) 771-8339 or jtalhelm@thestate.com