The latest target of Koch-backed organization are lawmakers, including Republicans, who backed the government spending bill. 

The group, Americans for Prosperity, is launching a "significant" six-figure voter persuasion campaign attacking ten Republicans and seven Democrats for backing the government spending bill that added $400 billion in government spending over two years. 

“It’s time to take a hard look at what lawmakers say, and what they actually do when it comes to reining in overspending," AFP spokesman Bill Riggs said in a statement. "The $1.3 trillion omnibus spending bill passed by Congress in March showed a complete disregard for fiscal responsibility. Both parties are responsible for putting the country on an unsustainable fiscal path." 

The two-year spending agreement by Democratic and Republican leaders in the House and the Senate was reached after months of negotiations that included a three-day government shutdown. The agreement, which increased domestic and military spending was supported by 145 Republicans and 111 Democrats. President Donald Trump, who was disengaged from the process until after it passed both bodies of Congress, said he'd never sign such a massive spending increase into law again. 

The campaign, which includes direct mail, print ads, digital ads and radio ads, is the first phase in a months-long effort to pressure lawmakers to rein in government spending. Of the ten House Republicans it targets, only one, Rep. Mike Bishop, R-Mich., has a challenging re-election, according to Cook Political race analysis. Another target, Rep. Lou Barletta, R-Pa., is running for the Senate against Democratic incumbent Bob Casey, but Barletta has not yet proven to be a threatening challenger. 

The ads will run in the lawmakers Congressional districts beginning Memorial Day Weekend and through the week while members are home for the week-long recess. 

The Koch organization, has had a successful week on Capitol Hill. Multiple pieces of legislation they've championed are heading to the president's desk for signature, including Right to Try bill that allows terminal patients to use pre-FDA approved pharmaceuticals, a roll back of Dodd-Frank banking regulations and a bill that allows veterans to use community health centers.