A new set of ad disclosures shows that Freedom Partners, a Koch brothers affiliate, is about to go on the air against a Democrat running for an open Senate seat in Michigan. The news comes one day after Sunlight reported that that Freedom Partners had begun airing ads in the Senate battlegrounds of Colorado and Iowa.

A station manager from WOOD, an NBC Grand Rapids, Mich. affiliate, confirmed that the Michigan ads were targeting Rep. Gary Peters, D, who is running for the seat that Democrat Carl Levin has held for 34 years. Levin will not be seeking reelection in 2014. Peters will face the winner of a competitive Republican primary.

Sunlight reported Monday that the Kochs’ formerly secretive nonprofit “trade association” is also blasting Democrats Mark Udall and Bruce Braley in Colorado and Iowa respectively, for taking thousands of dollars in campaign money from health insurance special interests.

The Rothenberg political report currently considers all three Senate races to be “leaning Democrat” — the only three Senate contest in 2014 to meet that criteria.

While it is not yet clear whether the Grand Rapids ads — which begin running Wednesday — will also ding Peters on healthcare, it wouldn’t be the first time that a group from the Koch network had done so. A March ad from Americans for Prosperity featured Julie Boonstra, a Michigan woman suffering from leukemia who told the camera that “because of Obamacare, I am now stuck with a plan that doesn’t work for me. My choice was taken away from me.”

The Freedom Partners’ ads, which first appeared in the political file of local CBS affiliate WWMT, will run between April 9 and April 29. The organization paid $26,700 for the air time at that station, where their ads will appear during the nightly news, the Price is Right and NCIS.

The latest ad disclosures in Michigan comes the day that Freedom Partners put out a press release about two earlier buys targeting Democratic senate candidates in Colorado and Denver. Those purchases cost the dark money group $1.1 million–but that price apparently doesn’t include the Michigan buy.

Jacob Fenton contributed to this report