After several months of slippage, Democrats believe South Carolina Superintendent of Education Inez Tenenbaum (D) has finally turned a corner in her open-seat Senate race against Rep. Jim DeMint (R).

Touting a new poll done for her campaign that shows Tenenbaum down only 3 points to DeMint, her campaign and the Democratic Senatorial Campaign Committee have begun bashing DeMint on the airwaves over his professed support for a national sales tax — an issue they believe could boost her back into contention.

“DeMint’s sales tax plan has been Topic A over the past three weeks of the campaign, and when voters hear about it, they really don’t like it,” said Tenenbaum’s communications director, Adam Kovacevich. He referred to the sales tax as “an albatross around [DeMint’s] political neck.”

Republican strategists acknowledge that the sales-tax issue has the potential to hurt them in the short term, but they believe a debate about taxes will ultimately work in their favor.

“The fact that we are arguing about taxes and Tenenbaum is the only candidate in the race that has called for a $1 billion tax increase shows this race is where we want it to be,” said National Republican Senatorial Committee Communications Director Dan Allen.

Americans for Job Security, a conservative organization independent of the DeMint campaign, ran an ad for several weeks in August that alleged that as her office spent “millions” on travel, Tenenbaum called for a huge tax increase.

Once considered a key element of the Democratic bid to retake the Senate majority they lost in the 2002 election, Democrats’ chances in South Carolina have rapidly eroded since DeMint defeated former Gov. David Beasley (R) in a June 22 runoff.

Tenenbaum’s campaign has struggled mightily this summer, dismissing both her campaign manager and her media consultant. DeMint has soared into a double-digit lead.

While the Tenenbaum campaign can’t avoid acknowledging its own struggles, officials point to a new poll done for her by Harrison Hickman that showed DeMint leading Tenenbaum, 44 percent to 41 percent.

The survey was conducted from Sept. 7 to Sept. 9, testing 600 likely voters. It has a 4 percent margin of error.

Among what the survey calls “definite” voters, DeMint leads by a slightly larger 46 percent to 40 percent.

The Hickman poll takers were in the field at the same time that Glen Bolger of Public Opinion Strategies, a Republican firm, conducted a survey for DeMint. It showed the Congressman leading 50 percent to 37 percent.

Both pollsters gauged black turnout as roughly 25 percent of the electorate when preparing their models. In the 1998 election, blacks made up one-quarter of the total votes cast, the highest percentage in recent memory. That turnout helped elect Gov. Jim Hodges (D), who lost his re-election bid four years later.

Republicans decried the Hickman poll as the latest evidence that panicking national Democrats are trying to widen the playing field.

Allen pointed out that just last week Hickman conducted a survey for the Democratic Senatorial Campaign Committee that showed Rep. Johnny Isakson (R-Ga.) with a narrow 46 percent to 41 percent edge over Rep. Denise Majette (D-Ga.).

Majette is seen by independent handicappers as a long shot and is not expected to receive a significant outlay of funds from the DSCC.

South Carolina is another matter, since it is already a DSCC target. The organization has already dumped $800,000 into the state in the form of independent expenditure ads — slightly more than half of the $1.2 million it has pledged to spend in the state this cycle.

By contrast, the NRSC has yet to even reserve time in the state for an independent expenditure campaign.

“They are spending more money than us,” said DeMint campaign manager Terry Sullivan. Spending that much “is going to close the race, but it is silly to say it is a four-point race.”

The latest of the DSCC ads hits DeMint on his support for a national sales tax.

“Jim DeMint wants to replace federal income taxes with a new 23 percent federal sales tax … on top of our state sales tax,” the spot’s narrator says, before detailing that the tax would include groceries, medicine and even the purchase of home.

“Maybe Jim DeMint can afford it, but not people who work for a living,” the narrator concludes.

The DSCC ad echoes that message in a commercial for Tenenbaum’s campaign, contending that DeMint will add “an extra 23 cents on almost everything you buy.”

As evidence of the effectiveness of this attack, the Tenenbaum campaign notes that DeMint is directly responding to the ads in new commercials of his own.

The DeMint ads note that the Congressman has never voted for a tax increase during his six years in the Senate and voted for 30 tax cuts in that time.

“Inez Tenenbaum supported largest tax increase in state history,” says the ad’s narrator. “That’s a record we just can’t afford.”