With concern growing in the Washington, D.C., Democratic community about the re-election prospects of Senate Minority Leader Tom Daschle (S.D.), the Democratic Senatorial Campaign Committee launched its first independent expenditure on his behalf Wednesday night.

The $600,000 ad buy signals the only foray into the race between Daschle and former Rep. John Thune (R) by Democratic-aligned third-party groups. The ad, according to knowledgeable sources, attacks Thune for his decision to become a lobbyist following his 2002 loss to Sen. Tim Johnson (D).

In June, Daschle pledged unilaterally to keep all third-party advertising on his behalf out of the state, but his spokesman said Wednesday that the Senator had not yet contacted DSCC Chairman Jon Corzine (N.J.) to request the ads be pulled.

“Senator Daschle has asked all third-party groups to stay out and he stands by that request,” said Daschle deputy campaign manager Dan Pfeiffer. “As Thune has said all along, we don’t have direct control over these groups.”

Corzine said that while he had initially planned to respect Daschle’s wishes and keep the DSCC out of the state, Thune’s decision to bring the South Dakota Senator’s wife into the political arena changed his mind.

In direct-mail appeals and print ads, the Thune campaign alleged that Linda Daschle’s position as a D.C.-based lobbyist has personally benefited the Senator on a number of occasions.

The ads have “gotten under a number of our skins,” said Corzine. “There is a point where you say enough is enough and you need to respond to the $9 million independent groups have spent attacking Tom.”

A number of independent conservative groups have sponsored ads that attack Daschle over the past 60 days.

Currently, the NRSC, the National Rifle Association, You’re Fired — a group financed by a wealthy California family — and the Club for Growth are on television in South Dakota with ads targeting the Democrat.

More than 7,000 gross ratings points of political ads are running in South Dakota as of today, meaning the average voter will see 70 campaign commercials in the space of the next week.

Thune campaign manager Dick Wadhams called the DSCC ads “another indication of Daschle saying one thing and something different happening in Washington, D.C.”

Wadhams added that the DSCC’s decision to take to the airwaves is a “reflection of what Democratic leaders are thinking about Tom Daschle right now.”

One Democratic consultant well-connected with the party apparatus said that while “this [race] has always been at the top of the radar screen because of who he is … now it is because of what the situation is.”

The consultant added that fretting over Daschle resembles “the concern people have with other red states. Bush may lose the [national] election but is going to do very well in the states.”

In 2000, Bush won South Dakota by 22 points. Several other “red” states are hosting competitive Senate races including Oklahoma, which Bush won with 60 percent, Alaska (Bush +31) and South Carolina (Bush +16).

The Daschle campaign and the DSCC rejected the idea that there is any concern about his prospects.

“Politics in South Dakota for a Democrat requires nerves of steel,” said Pfeiffer. “Daschle and his campaign team have been in much closer races than this one.”

Pfeiffer, along with campaign manager Steve Hildebrand, media consultant Karl Struble and pollster Al Quinlan all worked on Sen. Tim Johnson’s (D) 524-vote victory over Thune last cycle.

By all accounts, Daschle has put together perhaps the most extensive ground game ever in a Senate race; Thune’s absentee ballot program has been plagued with problems that led to the resignation of its director.

Brad Woodhouse, communications director at the DSCC, insisted that “there is no one here even remotely panicking about this race.”

Polling shows the race is a pure tossup.

The latest Daschle survey, conducted by campaign pollster Al Quinlan, showed Daschle with a 50 percent to 48 percent edge. It came out of the field Wednesday morning.

A Mason-Dixon survey released Sunday in the Sioux Falls Argus-Leader showed Daschle with a 49 percent to 47 percent lead, down from his 5-point edge in mid-September.

A John McLaughlin survey sponsored by the NRSC released earlier this week put Thune ahead 48 percent to 45 percent.

Another survey, which was conducted by Zogby International, is expected to be released within the next 24 hours.

Republicans believe that the Mason-Dixon survey does not accurately represent the state of the race because it was in the field prior to the airing of a new Thune ad that both sides concede carries a powerful message.

In the ad, Daschle is shown referring to himself as a “D.C. resident,” praising trial lawyers and saying he will always protect the “sacred right” of women to choose whether to have an abortion.

Given the glut of campaign ads on the air, however, it remains unclear whether any single ad can change the direction of the election.

In fact, even Wadhams admitted that “another mix of ads isn’t going to have any impact,” although he was referring to the new DSCC spot.