A torrent of money is flooding Charlotte TV stations as President Barack Obama and Mitt Romney battle for the 6 percent of North Carolina voters deemed undecided in the presidential race.

With the campaigns approaching the clubhouse turn, $7.6 million has been spent since August on presidential TV ads in Charlotte alone, or about $73 for every undecided voter.

And despite the video assault – ads are inundating every kind of program from “Dancing With the Stars” to “Late Show With David Letterman” – there appears to be little or no effect on voter attitudes.

“Right now the amount of money being spent here per each voter open to changing their mind is just staggering,” says Tom Jensen, director of Raleigh-based Public Policy Polling.

But Jensen sees little impact – his firm has found Obama and Romney locked within 3 points of each other in 25 of the 26 polls they’ve conducted since November 2010, and they appear dead-even at 48 percent each in the latest poll released Monday.

“We haven’t seen much of a shift,” he says. “I don’t know if it’s winning anyone over. It might just be getting on their nerves.”

Many of those in the 6 percent, Jensen believes, like neither Romney nor Obama or are apolitical.

“There’s a point of diminishing returns on TV ads and we may be getting to that,” says Jensen, who believes grass-roots efforts to get supporters to the ballot box may do more to decide the direction of North Carolina’s 15 electoral votes than the ad blitz.

Jensen’s findings are similar to the statewide Elon University Poll conducted in August in partnership with The Charlotte Observer that showed 47 percent of likely voters said they would cast ballots for Romney and 43 percent for Obama. Six percent of respondents said they didn’t know or were undecided. Elon’s poll had a margin of error of 3 percentage points. Other polls since then have found the race to be essentially tied, with perhaps a slight edge to Obama.

While Obama’s campaign has outspent Romney’s about 3 to 2, Romney benefits by commercials aired by conservative political action groups enabled by a recent Supreme Court decision and spending by the Republican National Committee. When RNC and PAC spending is added to Romney’s column, he outspends Obama about 4 to 3 in Charlotte, a trend borne out statewide.

Program strategies differ

Charlotte ranks No. 8 nationally among media markets with the biggest political ad buys, according to the nonprofit Institute for Southern Studies.

In the presidential race, both campaigns spend heavily on ads on local news programs, which are seen as attracting a more politically engaged audience. All ads on local news shows are also controlled by the stations rather than the networks, meaning there is more time available to buy.

Romney has been more active in buying time on sports programming, beginning with spots on the Olympics in August, followed by PGA golf and U.S. Open tennis.

Romney has spent substantially in Charlotte on NFL football, too, buying up to three 30-second commercials on recent Panthers games at a cost of $18,000 each. Pro football is considered the “apple-pie buy” in advertising because it reaches such a diverse audience – men and women, young and old, black and white.

It also brings in a huge audience. Romney bought three ads on Fox Charlotte on Sept. 16, when the Panthers beat the Saints. That game was watched in a quarter of all Charlotte households, and of the TVs turned on that afternoon, 44 percent were tuned to the game. It was the No. 1 rating for any show that week by far.

Obama tends to buy prime-time spots on shows that tend to skew younger, such as “Modern Family” and “X-Factor.”

Speculation that Obama might abandon the North Carolina airwaves late in the campaign has proved unfounded. He has already reserved ad time up to Election Day, while the Romney campaign tends to buy time about 10 days in advance.

Local ad squeeze

As the airwaves fill with campaign commercials, it puts pressure on local firms that find it more difficult to buy time to advertise their wares.

In the 60 days before Election Day, federal candidates are guaranteed by law the lowest ad rates that stations offer any other advertiser. Because television ad time is limited and political messages take so many of the available spots, prices get pushed up on other advertisers.

Nancy Haynes, a principal in the Charlotte ad agency Collins, Haynes and Lully, says one of its clients usually does a TV campaign this time of the year, but the agency is pushing it to December and January because political advertising has pushed prices too high.

“You can probably also make a case that it’s less valuable now because people are fast-forwarding more because they’re tired of negative campaign ads,” she said.

Jim White, station manager for Fox Charlotte (WCCB, Channel 18), says stations try to protect their long-term clients, but the glut of political ads does drive up rates. “If there’s suddenly a demand that can’t be met by the number of ad units you have available, things go up. It’s a supply-and-demand business.”

Additionally, he says, since the onset of the recession, advertisers tend to forgo long-term ad buys, preferring to buy time closer to when the spots will run. That means it may be more difficult to find openings for their messages.

Long political season

White says this political cycle is much different from 2008, when presidential campaigns didn’t recognize North Carolina as a toss-up until the final weeks. In an ordinary election year, he says, there is a spike in the spring for the primaries and most of the rest of the spending comes from mid-September to Election Day.

Joe Pomilla, general manager of WSOC (Channel 9), says that core local advertising had been up about 5 percent in the first half of the year, signaling a recovery in sluggish sales during the recession. But the summer-long surge in election spending was a surprise.

“June, July and August have been beyond what we expected,” he says.

Campaign advertising, particularly in the presidential race, should buoy the fortunes of stations in swing states this year. In Charlotte, the major stations are expected to hit their revenue targets for the year in late October or early November if the trend holds up.

“Obviously, it really does help the bottom line,” says Pomilla, whose station has reaped more in presidential ad sales because of its dominant ratings in news shows. “Certainly better than the last couple years.”