House Majority PAC is launching a new ad hitting Rep. Nick RahallNick RahallLikely W.Va. Senate GOP rivals spar in radio appearances West Virginia is no longer Clinton country Solution needed: Rail congestion is stifling economic growth 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 JenkinsGOP trains focus on opioid abuse West Virginia Republicans urge governor to reject climate rules Lawmakers visit oil train explosion site 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."