Weeks away from the Aug. 7 primary that will choose her Republican opponent, U.S. Sen. Claire McCaskill, D-Mo., has taken the unusual step of launching a new TV ad campaign that consists of three spots – each targeting one of her three best-known Republican contenders.

Such a move appears unprecedented in Missouri politics. Incumbents usually stay out of the opposing party’s primary – or, in rare cases, run an ad blasting the opposing candidates as a bloc.

The ads, first disclosed by the political website Politico, began airing Thursday night statewide. McCaskill’s campaign declined to say how long they will run or how much will be spent. All are attack ads, each focusing on either U.S. Rep. Todd Akin, businessman John Brunner or former state Treasurer Sarah Steelman.

McCaskill’s campaign said in a statement that the aim is to highlight “vulnerabilities all three candidates seeking the Republican nomination for U.S. Senate face in the general election. With no clear front-runner and mounting attack ads against Claire McCaskill, her campaign is shedding truth on the individual records of each of her potential opponents as opposed to waiting three weeks until the GOP primary.”

But some activists, notably Republicans, speculate that McCaskill’s ads offer a hint of which candidate she’d prefer to run against – and which one she fears the most.

Her anti-Akin ad, said one consultant privately, “looks like an ad for Todd Akin.” He’s attacked as “a true conservative who’s just too conservative,” and cites his calls to eliminate several federal agencies and his opposition to “big government.”

Another Republican source said that the media buys tracked by the GOP indicate that most of McCaskill's ad money is being spent to air the Akin ad.

Steelman is portrayed by McCaskill in her attack ad as “more politics as usual.” The spot blasts Steelman's “contributions from big contributors” and accuses Steelman of “more inside deals, taking thousands of gifts from lobbyists in just her first five months in office.”

But McCaskill’s ad against Brunner is arguably the harshest, with attacks more likely to resonate with the public. With ominous music in the background, an announcer asserts, “Since 2000, Brunner hasn’t even bothered to vote in 16 elections. And as a CEO, the media reports Brunner nearly killed the family business. And ran $245 million in debt.”

Brunner fielding three waves of TV attacks

McCaskill’s anti-Brunner spot is similar to TV attack ads that Steelman and the Democratic-aligned Majority PAC-- with ties to U.S. Senate leader Harry Reid, D-Nev. -- also have been running against him. All seek to debunk Brunner's image as a successful and savvy businessman. 

One Republican consultant said the anti-Brunner approach from all three camps, even though not coordinated, appeared similar to the direction taken  by national Democrats to attack likely Republican presidential nominee Mitt Romney, who also is emphasizing his business acumen.

(Brunner, in turn, has been slamming Steelman and Akin as big spenders akin to McCaskill and President Barack Obama. )

Said Brunner campaign spokesman Todd Abrajano: "It's obvious that Harry Reid and Claire McCaskill are launching false attack ads against John Brunner in a blatant attempt to influence and manipulate Republican primary voters because the Democrats know that John Brunner is the only one who can defeat McCaskill in November.

"McCaskill's transparent attempt to prop up Todd Akin is laughable and will ultimately backfire when John Brunner wins the Republican nomination," Abrajano added.

Said Steelman spokesman Patrick Tuohey: "Sen. McCaskill is advertising in the GOP primary so that she can choose her opponent in the general election. It's clear based on the content of the advertising that's she'd like to run against Todd Akin. It's easy to see why. Given Akin's stand on earmarks, McCaskill will be able to cast herself as the fiscal conservative."

He added, "Sarah, meanwhile, is the only candidate from outstate and she's carried rural Missouri in previous elections. McCaskill was able to win rural votes against Talent, but she won't be able to do so against Steelman. Furthermore, Steelman won't permit McCaskill to run gender wedge issues."

Akin spokesman Ryan Hite said that any effort by McCaskill to help him in the primary would likely lead to her defeat in November. "I don't see why she would want us in front. Akin has the strongest contrast to her record,'' Hite said.

"Missourians don't agree with her voting record. They'd rather have someone like Todd,'' Hite added, citing Akin's opposition to Obamacare and McCaskill's support for it. "It would not be wise for her to seek having Todd as her general election opponent."

Democrats laud her strategy

McCaskill and her campaign have denied singling Brunner out for defeat or helping to boost Akin.

But some Democratic activists and consultants privately are concerned about Brunner because he has the most money of any of the Republicans and is largely funding his campaign himself. He already has spent close to $5 million of his own money and is expected to spend far more in the general election.

Local Democratic consultant Mike Kelley, former executive director of the state party, said he believes that McCaskill's three-ad approach is unprecedented in Missouri during the opposition’s primary.  But he agrees with her general objective.

“She’s putting a spotlight on how out-of-touch they all are with everyday Missourians,’’ he said.

Kelley contended that McCaskill’s ads should also appeal to independent voters who may not vote in the primaries but will show up at the polls in November. The GOP ads by all the candidates, he said, have focused too much “on reassuring their base and making their base feel good,’’ while ignoring the independents who likely will swing the general election.

Consultant Richard Callow said that McCaskill’s three-ad approach was unusual and innovative. It also makes sense, he added.

“She’s polling neck-and-neck with each of them,’’ Callow said, so it makes no sense for her to single out a particular Republican in an ad campaign -- or to lump all three in the same ad.

At the same time, he continued, it would be dangerous for McCaskill to stay out of the Republican primary and cede the pre-primary TV airwaves to the three rivals, as they tout their credentials and jab at hers.

Running three attack ads, said Callow, will provide “a certain amount of (media) buzz” – in other words, free publicity – while also allowing her to test out subsequent attacks against the eventual GOP nominee. 

Concluded Callow: “She’s one smart cookie."