House Majority PAC is launching a new ad hitting Rep. Nick RahallNick Joe RahallWe shouldn't allow politics to impede disaster relief Break the cycle of partisanship with infant, child health care programs Clinton mulls role in 2018 midterms MORE’s (D-W.Va.) Republican opponent for his support from the billionaire Koch brothers.

The ad, from a super-PAC working to elect Democrats to the House, charges that Charles and David Koch have spent more than $1 million to elect state Sen. Evan JenkinsEvan Hollin JenkinsBlankenship third-party bid worries Senate GOP Blankenship to run third-party Senate campaign after losing GOP primary Blankenship wants to 'make sure' Morrisey doesn't win Senate bid MORE, and outlines a series of negative impacts from Koch spending and influence in West Virginia.

“The Koch brothers wouldn’t be billionaires if they didn’t get what they paid for,” a narrator says in the ad. “In Washington, Evan Jenkins won’t work for us.”

The ad is part of an ongoing barrage of attacks from House Majority PAC on Jenkins in the district, and the group is extending its buy by another $70,000 to air the new ad in the Charleston-Huntington and Bluefield-Beckley markets.

Rahall is a top Republican target this cycle and has taken his own knocks from the Koch-backed Americans for Prosperity over the past few months, as well as a recent attack ad from Jenkins that calls Rahall a "lying politician, just like Obama."