The new ad from Freedom Partners Chamber of Commerce, a hub of the Koch donor network, comes at Sen. Tammy Baldwin (D-Wis.) from a surprising angle — attacking her as a foe of the little guy. In the spot, one of three now running in Wisconsin, a narrator talks over hard-rocking guitar and images of blue-collar workers.

“The hard-working folks simply can’t afford to send more money to Washington,” says Chris, the narrator. “If Tammy Baldwin opposes tax reform, she opposes jobs; she opposes higher wages.”

The ad is one of several, now in rotation, that attempts to reframe attacks on liberal politicians as cries from the populist gut. In this spot, “Chris” is identified as the president of Northwest Builders; his full name is Chris Mlejnek, and in 2015 he gave $2,500 to a super PAC created to help elect Gov. Scott Walker (R-Wis.) to the presidency.

But other ads designed to build support for a tax overhaul follow along the same theme. In “laid off,” an ad that began running when the House GOP pivoted from health care to taxes, the America Action Network hands the microphone to a metalworker who blames America’s complicated tax code for a job he lost. “Thousands of jobs like mine are lost to countries like China,” he says.

In “Paycheck to Paycheck,” a homemaker suggests that any tax cut passed by Congress would help her family — from the context, a working-class family — pay the bills. “I’d like to see Congress make middle-class tax cuts a priority,” she says. “And closing loopholes means everyone pays their fair share.”

Similarly, in Massachusetts, a PAC largely funded by the Mercer family — Massachusetts First — has been on the air for weeks with a spot that hits Sen. Elizabeth Warren (D-Mass.) not for anything moving through Congress, but for her salary as a Harvard Law School professor.

“She was paid a salary of nearly $350,000 — for teaching a few hours of classes each week,” sighs a narrator in the spot. “The real irony? While Warren was raking in hundreds of thousands each year, many of her students were taking on massive debt to listen to Warren lecture them on… bankruptcy. Hypocrite professor Elizabeth Warren: huge salaries for her … rising costs and crushing debt for families and students like you.”