Billionaire Koch brothers have already spent more than $4.3M against Tammy Baldwin.

MADISON - Wisconsin Republican U.S. Senate candidates Leah Vukmir and Kevin Nicholson are vying for a new round of out-of-state billionaire admirers.

Each already bankrolled by a right-wing billionaire to call their own, Vukmir and Nicholson have for months championed Washington corruption and advocated right-wing policies that put corporate special interests first and would inflict real harm on Wisconsin and hardworking Wisconsin families.

Vukmir and Nicholson’s efforts haven’t gone unnoticed: the Republicans have caught the attention of the out-of-state billionaire Koch brothers, who have already spent more than $4.3 million against Tammy Baldwin and are sponsoring tonight’s U.S. Senate candidate forum via their Americans for Prosperity front group.

Tonight’s U.S. Senate debate between Leah Vukmir and Kevin Nicholson -- who are engaged in a “unity” pledge-shredding primary characterized by deeply personal and petty attacks -- is less a debate and more an audition; a chance for Vukmir and Nicholson to show the Kochs that they’d work for them, not Wisconsin.

"Tonight, Leah Vukmir and Kevin Nicholson are auditioning for the Koch brothers -- each hoping to earn the backing of even more out-of-state billionaires,” said Brad Bainum, DPW spokesperson for the 2018 Senate race. "That’s why Vukmir and Nicholson are running hard to the right on a Koch-backed agenda that includes tax breaks for billionaires and powerful special interests at the expense of the middle-class; cuts to Social Security and Medicare; and the GOP’s disastrous plan to take away millions of Americans’ health insurance.

"Nicholson and Vukmir are all too eager to sell out Wisconsin in exchange for doing the bidding of their powerful special interest backers in the U.S. Senate."