The Republican Party of Wisconsin rolled out a pledge Wednesday calling on all Senate candidates to support the eventual nominee, an attempt to calm what could be a potentially bruising and expensive GOP primary in the race to unseat Sen. Tammy Baldwin Tammy Suzanne BaldwinKeep teachers in the classroom Cher raised million for Biden campaign at LGBTQ-themed fundraiser Democrats seek balance in backing protests, condemning violence MORE (D).

Candidates who sign the “unity pledge” are required to back whoever emerges from the Aug. 14 GOP primary. That will also allow them to be considered for an endorsement by grass-roots conservatives who vote on that when they attend the state party’s convention later this year.

Kevin Nicholson, a Marine Corps veteran and businessman, and state Sen. Leah Vukmir are so far the only two Republicans in the race, and both campaigns confirmed to The Hill that they’ll sign the pledge.

ADVERTISEMENT

Nicholson and Vukmir will now gain access to the list of potential delegates and can start contacting them ahead of the endorsement process. Nearly 2,500 delegates will be selected throughout the state to attend the convention. Those delegates will vote on whether they want to make an endorsement in the months prior to the August primary.

Sen. Ron Johnson Ronald (Ron) Harold JohnsonSecond GOP senator to quarantine after exposure to coronavirus GOP-led panel to hear from former official who said Burisma was not a factor in US policy The Hill's Morning Report - Sponsored by The Air Line Pilots Association - Trump contradicts CDC director on vaccine, masks MORE (R-Wis.), who had his own highly competitive race in 2016, will be the chairman of the grass-roots endorsement process and called on all Republicans running to sign the pledge as they look to take on Baldwin in November.

“Wisconsin needs a person of integrity supported by the good folks of our state to help advance conservative reform and take on Washington’s professional political class,” Johnson said in a statement. “That person will need Wisconsin’s conservative grassroots to win.

The pledge was unanimously approved in early December and Republicans with knowledge of the process say it’s a proactive measure to unify the party and “not a reaction to any one piece of news.”

Republicans feel more emboldened about the seat after President Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE eked out a win in Wisconsin in 2016 by less than a point. The race had already drawn millions of dollars prior to 2018 and the GOP field has the potential to grow.

ADVERTISEMENT

Wealthy businessman Eric Hovde is still considering a Senate bid and said back in December that he hasn’t “finalized the decision.” He unsuccessfully ran for the upper chamber in 2012. If he decides to throw his hat in the ring, he’ll also be asked to sign the pledge.

Both Nicholson and Vukmir have earned prominent endorsements and have people with deep pockets in their corners.

Nicholson has the backing of GOP mega-donor Richard Uihlein, who’s pumped millions of dollar into a super PAC that endorsed Nicholson. He’s also scored endorsements from conservative groups Club for Growth and FreedomWorks for America as well as from Great America Alliance, a pro-Trump super PAC with ties to former White House chief strategist Stephen Bannon.

A Nicholson spokesman told The Hill that Nicholson will sign the pledge and “he hopes that all Republicans will unite behind our nominee to defeat Baldwin."

Turning to Vukmir, billionaire Diane Hendricks is serving as her finance co-chair and Mary Kohler, who’s the widow of the late GOP activist Terry Kohler, will also be on her campaign committee.

“As a lifelong Republican, I’ve always supported the party nominee and you can bet I’ll be doing everything I can this November to make sure Wisconsin has a senator who believes in the Wisconsin Way,” Vukmir said in a statement. “Senator Johnson certainly understands that the grassroots are the core of Wisconsin’s Republican Party, a focus I have built my candidacy on.”

So far, Nicholson has outpaced Vukmir in fundraising, though Vukmir was only an announced candidate for three weeks of the third fundraising quarter while Nicholson was a candidate for nearly the entire quarter.

Nicholson raised more than $400,000 between July and September and ended the month with $345,000 cash on hand. During that same time period, Vukmir raised about $242,000 and ended that quarter with around $233,000 in the bank.

Wisconsin Democrats responded to the pledge, arguing that it already shows that the GOP primary has become divisive.

"The fact that Wisconsin Republicans need a unity pledge shows how nasty their primary has become," said Brad Bainum, a spokesman for the Democratic Party of Wisconsin.

"But -- no matter who the nominee is -- both Vukmir and Nicholson are willing put their billionaire donors and special interests ahead Wisconsin by driving up the cost of health care and working to cut Wisconsinites' Social Security and Medicare."

Updated at 2:35 p.m.