Third party ads were launched almost simultaneously Wednesday targeting likely opponents in November’s Missouri U.S. Senate race.

Sen. Claire McCaskill, D-Missouri

Americans for Prosperity, a free market group that favors GOP candidates, is spending $1.8 million on a TV, cable, and digital campaign against incumbent Democrat Claire McCaskill.

The spot criticizes her use of a private plane while on an RV tour as well as her opposition to the Republican tax cut passed late last year.  It also claims she voted for a trillion dollars in tax increases on items such as Obamacare.  The ad further accuses McCaskill of touting bipartisanship when her real loyalty is to Democratic Senate Leader Chuck Schumer and the party.

The spot is titled “Tax Reform Double-Talk” while a new ad targeting Republican Senate challenger Josh Hawley from Senate Majority PAC is named “Golden”.

It singles out Hawley for his alleged connection to Joplin businessman and megadonor David Humphries and accusations of a pay-to-play scheme.  The ad claims Hawley, in his role as state Attorney General, declined to investigate Humphries over a pay-to-play arrangement with lawmakers after Humphries and his family gave $4.5 million in what amounted to 75% of Hawley’s campaign funding in 2016.

Attorney General and Republican candidate for U.S. Senate Josh Hawley

The ad is a sequel to Senate Majority PAC’s previous statewide spot that also focuses on Hawley’s alleged link to Humphreys.  Humphreys is accused backing state lawmakers who would craft bills to shield his building products business from lawsuits stemming from faulty roof shingles.

Senate Majority PAC is a Democratic super PAC with a large donor base that supports Senate campaigns.  It was formed in 2011 as a response to heavily financed ad campaigns organized by Republican operative Karl Rove after the 2011 Citizens United court decision allowed for unlimited spending.

Americans for Prosperity (AFP) is bankrolled by the wealthy libertarian activist Koch Brothers.  It’s produced three ads against McCaskill in 2018.

The organization spent seven-figure sums in February and March for spots which, like its latest ad, criticizes the two-term Senator for voting against the tax overhaul.  It’s unclear how effective such efforts are as the legislation is becoming more unpopular over time.

A Monmouth University Poll from late June showed support for the Republican tax reform package at just 34 percent versus a 41 percent disapproval rating.  In January, shortly after the measure passed, respondents were evenly split at 44 percent for both approval and disapproval.

The AFP ad also plays on McCaskill’s standing as a wealthy person by noting her use of the private plane during the RV tour.  The tactic has often been used to portray her as out of touch with every day, working people.  It hasn’t been effective yet in bringing her down.

Regardless of the impact of the new ad against McCaskill, it’s drawn a quick response from her campaign.  In a release this morning, the campaign defended her use of her husband’s company’s plane as a means to get around the state to meet more Missourians at no cost to taxpayers.

The release disparages the AFP ad as an effort by “dark money megadonors” who have “doubled down on their efforts to prop up Hawley’s struggling campaign with a misleading attack ad on Claire McCaskill’s record.”

Polling between Hawley and McCaskill has been tight.  A survey earlier this month from the Republican-affiliated Remington Research Group pegged Hawley with a two-point edge.

Although he considered to the frontrunner, Hawley is facing 10 opponents in the August 7th primary.