COLUMBIA, S.C. » They have been inescapable: growling baritone announcers and grainy images of sneering candidates. Mitt Romney is a corporate raider. Newt Gingrich’s politics are desperate and disgusting.

Anyone who happened to be near a working television in South Carolina this weekend was exposed to one of the most concentrated and expensive barrages of political advertising that this state has experienced. With the traditional efforts of candidates now multiplied by the presence of the well-financed super PACs supporting them, political operatives furiously outbid and outmaneuvered each other in a last-minute scramble to buy up their share of the airwaves between now and the primary on Saturday and makes sure their messages do not get drowned out by those of their rivals.

Want to advertise on "60 Minutes," as Romney did on Sunday? His campaign had to get WLTX, the CBS station here, to bump a super PAC that was actually running ads supporting him. It agreed to pay $3,000 for a 30-second spot — $100 a second, almost double the usual rate.

Rick Santorum, running as a family values social conservative, put his campaign’s money into the very Hollywood studios he so often derides, booking time on NBC during the Golden Globe awards and "30 Rock."

And super PACs, eager to be seen during the NFL playoff game on Saturday featuring the Denver Broncos’ Tim Tebow, bought up slots that were spoken for weeks ago, paying premiums to knock advertisers like Hardee’s, Jeep and the Ford Motor Company to later times.

"It’s like carpet-bombing," said Scott Sanders, general sales manager for WIS, the NBC station in Columbia. "They’re waiting until the last two weeks to reach everyone they can. He who shouts the loudest, last might win."

The arms race at television stations across South Carolina is the most vivid manifestation yet of the influx of outside money into U.S. politics this election cycle. Thanks to a Supreme Court decision that paved the way for the creation of the so-called super PACs — groups that can raise and spend unlimited amounts of money advocating for a candidate as long as they do not coordinate with the campaign — the messaging wars are growing to new levels of intensity.

Five Republican presidential candidates are advertising on television here. In addition, seven super PACs have run commercials alongside them. (Romney has two groups taking up his cause, Restore Our Future and Citizens for a Working America. And a PAC supporting Jon M. Huntman Jr. has been advertising here, though Huntsman himself has not.)

Candidates and super PACs have committed nearly $9 million to advertising here on broadcast television since the beginning of December, according to figures provided by a Republican strategist who closely monitors media spending. In 2008, when five Republican candidates were spending heavily here, the amount spent on broadcast was $6.9 million, according to Kantar Media’s Campaign Media Analysis Group. With the addition of three Democratic candidates, total spending in 2008 rose to $13.5 million.

When radio and cable are factored in this year, the total committed so far approaches $11 million.

The spending is reaching record levels even though the candidates and the PACs did not start advertising heavily here until last week, a departure from other years when commercials would start in the fall.

"What you’ve got is two and a half months of advertising compressed into a two-week period of time," said Rich O’Dell, general manager of WLTX, the CBS station in Columbia. O’Dell said that he thought campaigns might forgo television advertising in South Carolina this year, as many of them did in New Hampshire. Then, he said, "As soon as Iowa was over: Boom." Because of the way television advertising is sold, many advertisers buy what is called pre-emptable time, which is discounted with the caveat that another buyer could come in and take the slot by offering a higher price. As the candidates and outside groups swept in offering more money, stations were left tearing up their ad schedules, jettisoning their usual slate of commercials from car dealerships, furniture wholesalers and makers of medical alert bracelets.

At WLTX, much of the last-minute reshuffling was around the NFL playoff games on Saturday and Sunday, where 30-second blocs were being sold to super PACs like the Red, White and Blue Fund, a pro-Santorum group, and Citizens for a Working America, which is for Romney, for as much as $5,000 — about double the rate they would ordinarily fetch.