Des Moines, Iowa CNN  — 

Wisconsin Gov. Scott Walker can’t escape the divisive battles with union workers that have defined his tenure as governor – not even in Iowa.

The Republican presidential candidate faced boos and chants of “liar” from dozens of protesters who drove down from Wisconsin as he stumped Monday at the Iowa State Fair Des Moines Register soapbox, and the heated incident devolved into physical altercations between supporters and demonstrators.

As the protesters shouted, Walker seized the opportunity to highlight his record as a fighter who faced off against unions in Wisconsin and became the first governor to successfully fight an effort to recall him from office.

“I am not intimidated by you sir or anyone out there,” Walker said to one heckler. “This is what happened in Wisconsin. We will not back down, we will do what is necessary.”

Walker’s affiliated super PAC is named “Unintimidated PAC” – a nod to his successful fights with organized labor since taking office in 2011, including surviving a recall election.

As Walker fired back verbally from the stage, his supporters physically grappled with some of the protesters in the crowd.

Toward the end of his speech, several protesters toward the front, sitting in front of the bales of hay below the soapbox stage, held up yellow signs reading “WARNING: don’t let Scott Walker do to America what he did to Wisconsin.” The protesters held the signs in front of Walker.

As Walker supporters tussled with the union protesters and tore the posters, the protesters pulled out new posters. Matthew Desmond of the political website was one who had his anti-Walker sign torn.

“I got pushed into a disabled woman,” Desmond said in an interview with CNN. “I fell on her wheelchair. She started screaming at me.”

As Walker took questions after his speech from large and energetic crowd near the Soapbox, Ciara Fox of Milwaukee yelled to interrupt him.

“200,000 jobs you promised Wisconsin. Where are they at?”

“Black lives matter!” she continued, part of a group of nearly 50 people who took a bus from Wisconsin to protest Walker’s policies. The group advocates for a $15 minimum wage and better health benefits.

Walker repeatedly looked to fire up supporters in the crowd to drown out the boos, touting his record in Wisconsin and insisting that “if we can fix a blue state like Wisconsin, we can fix America.”

In a press gaggle after his speech, Walker reminded reporters that he is “used to that,” saying that the protests were a result of the “big bold reforms” he implemented in Wisconsin.

Asked how he could unite the country when his mere presence is consistently cause for such divisiveness, Walker told CNN that is the price for achieving real reform.

“I think you’ll see the same thing in America. Early on if you’re going to push real reform, if you’re going to challenge the status quo, there are always going to be people in both parties who don’t like people who challenge the status quo,” Walker said. “If given the chance to be President of the United States I want not just to talk about fighting, I’ll fight to challenge the status quo in Washington, I will win that fight, we will get results and we’ll do it ultimately without compromise.”

The protesters also refused to back down, trailing Walker as he took questions from reporters and following him as he walked out into the fair.

“How are you going to run for president when you ain’t even got the state of Wisconsin together?” Mary Jacobs, a 47-year-old personal care worker from Wisconsin said.

Confrontations with Iowa State Fair audience members can often shape perceptions of candidates and provide key news clip fodder throughout the campaign.

One of the key moments in the 2012 campaign came when Mitt Romney got into a back-and-forth with a heckler about taxing corporations at the same venue of the Iowa State Fair.

Romney’s reply that “Corporations are people” quickly became a meme during the race and ultimately fed into the Democratic narrative of 2012.

CNN’s Tom Lake and Betsy Klein contributed to this report.