Kevin Binversie, writing for the Weekly Standard, says there is concern that the Club for Growth controversy in the Republican primary battle in the U.S. Senate race could be a foreshadowing of a return of the bitter primary fight from 2012 in Wisconsin.

“All this Christmastime back and forth has raised concern among Badger State Republicans that a repeat of the 2012 GOP Senate primary is imminent,” Binversie wrote. “In that race, a flurry of interference from out-of-state groups created a bloody primary, which essentially handed the general election to Madison liberal Tammy Baldwin. Republican primary winner and former Gov. Tommy Thompson spent the race raising money and not answering the millions of dollars in ads Baldwin’s campaign was airing across Wisconsin.”

During the 2012 GOP primary for the U.S. Senate, Thompson had to endure attacks from businessman Eric Hovde and former Congressman Mark Neumann, and the effort exhausted Thompson’s campaign fund. By the time Thompson was able to recover, Baldwin had framed the race by claiming Thompson was out of touch with Wisconsin. It also didn’t help Thompson that President Barack Obama carried the state 53 percent to 46 percent in 2012. Thompson lost 51.5 percent to 46 percent.

Shortly before Christmas, the national Club for Growth submitted an op-ed to RightWisconsin defending their endorsement of Nicholson by criticizing Vukmir’s record including voting for the 2011 and 2015 state budget bills. In addition to criticism from conservative talk radio, Club for Growth was harshly criticized by Americans for Tax Reform.

“This concern has gotten so strong, Sen. Ron Johnson and the state GOP recently created a “Unity Pledge” to avoid a repeat of six years ago,” Binversie wrote. “Both the Nicholson and Vukmir campaigns have indicated their intentions to sign the pledge.”

While the pledge does touch on the conduct of the campaigns by including a promise to run “a campaign focused on defeating Senator Tammy Baldwin,” the real purpose was to ensure that the campaigns behave at the state convention and endorse the eventual winner of the August primary.

It’s unlikely that the “unity pledge” will prevent the campaigns from criticizing each other. Vukmir has already criticized Nicholson over his endorsement by Steve Bannon which Nicholson refused to repudiate after Bannon was quoted attacking the Trump family. Johnson already said publicly that Vukmir’s criticism of Nicholson did not violate the pledge. Nor does the “unity pledge” bind outside actors like Club for Growth.

Binversie also says that the national Club for Growth was invited by RightWisconsin to explain their endorsement of Nicholson. While I welcomed the op-ed, Club for Growth submitted it unsolicited in response to another op-ed we ran criticizing them for previous attacks on Vukmir. The controversy and complications they created for their preferred candidate was their own doing.

Nicholson, so far, has not answered whether he would have voted for the state budgets that were criticized by Club for Growth, nor has Nicholson said if he agreed with Club for Growth’s criticisms of Vukmir.