The political arm of anti-tax crusaders the Club for Growth finally took a side in the GOP primary contest to replace Rep. Kenny Hulshof (R) late last week, endorsing state Rep. Bob Onder (R) and buying $100,000 worth of television ads hammering his main primary opponent.

“Blaine Luetkemeyer, a conservative?” the 30-second spot begins, referring to the former state legislator. “Not on taxes and spending: Luetkemeyer pushed to make it easier to raise property taxes; he voted to increase state debt by billions; Luetkemeyer voted to authorize a new tax to pay for sports stadiums in Kansas City.”

“And stunningly, when we’re paying four bucks a gallon, Luetkemeyer is against cutting the gas tax,” the ad concludes. “Does that sound conservative to you?”

Onder, a physician, and Luetkemeyer, who also served as the Show Me State’s tourism director in addition to his stint in the Legislature, both vigorously lobbied for the Club for Growth nod, which was announced Thursday.

“If voters in Missouri’s Ninth Congressional District are looking for a true economic conservative, it is clear that Blaine Luetkemeyer is not their guy,” Club for Growth President Pat Toomey said in a statement. “Luckily, there is a real economic conservative in this race and his name is Bob Onder. Though he [has] only served two years in the state legislature, Onder quickly amassed a record of cutting taxes and fighting for greater economic freedom.”

Meanwhile, as the Club for Growth aired ads attacking his economic record, Luetkemeyer shot back with a new television ad claiming “Congress has broken the bank.”

“Blaine Luetkemeyer knows Congress is broken and that neither Democrats nor Republicans have done enough to stop runaway government spending,” the ad begins. “America is $9 trillion in debt. We’re mortgaging our children’s future.”

On the Democratic side, former state Speaker Steve Gaw has also taken to the airwaves with a new TV spot focusing on soaring medical and gasoline costs.

“There are two things we all know: the price of gas and the cost of prescription drugs,” he says as the ad begins. “In Congress I’m going to take on the big oil and drug companies, just like when I stood up to the big utility companies in Missouri, when they tried to raise your rates.”

The Aug. 5 primary includes five Republican and four Democratic candidates.