All three candidates - Todd Akin, John Brunner, and Sarah Steelman - released new television ads this week critical of each other.
While the three are almost identical on policy - all three are running as Tea Party conservatives - the three are seeking other ways to highlight nuance.
Steelman hopeful launched her latest television ad Tuesday morning critical of rival John Brunner's business history during his tenure as CEO of Vi-Jon, a St. Louis pharmaceutical manufacturing firm.
"John Brunner: Sued for failing to pay taxes," the ad said. "Brunner claims to be against pork barrel spending, but his business received millions in government handouts."
The ad states that Steelman would oppose debt limit increases as a U.S. Senator.
The Brunner campaign denounced the ad Tuesday, claiming that Brunner was never personally sued for paying taxes. Instead, Brunner's company - Vi-Jon Laboratories - was sued for late taxes while Brunner was CEO. The campaign said the taxes were repaid in full.
The campaign also took issue with the claim that Brunner took "government handouts" in the form of tax credits. Brunner's campaign said Brunner accepted tax credits available to all Missourians, including tax credits that Steelman voted for during her time in the state Senate.
In his own new ad, launched yesterday, Brunner jabbed Akin for his previous musings in favor of the idea of an individual mandate for health care, as well as Steelman for voting against tort reform legislation.
The Akin campaign pointed out earlier this month that Akin never introduced the legislation, and Steelman's campaign cited her opposition to a drunk driving loophole in the tort law changes she opposed.
Akin also released an ad that - without explicitly naming names - subtly jabs Brunner for his increased use of negative ads.
"Don't be fooled by false, negative attack ads against conservative Todd Akin," said former Arkansas Gov. Mike Huckabee in his second ad for Akin.
In the coming weeks, Missourians can expect more campaign ad spending as the primary race moves closer to Aug. 7. Brunner has shown his eagerness to invest his own personal campaign funds in the race, and Steelman has a super PAC with nearly $400,000 sitting on the sidelines for the final weeks.