MILWAUKEE — Making her 2015 debut in Scott Walker’s home state of Wisconsin, Hillary Clinton on Thursday unleashed her harshest and most extended diatribe yet against a Republican rival not named Donald Trump, accusing the governor of being a tool of the billionaire Koch brothers.

“It seems to me, just observing him, that Governor Walker thinks because he busts unions, starves universities, guts public education, demeans women, scapegoats teachers, nurses, and firefighters, he is some kind of tough guy on a motorcycle, a real leader,” Clinton said to a packed audience at the University of Wisconsin-Milwaukee. “Well, that is not leadership folks. Leadership means fighting for the people you represent."

While Clinton frequently criticizes her Republican opponents on the campaign trail, her barbs are rarely so extended or pointed. She also mentioned Donald Trump, Jeb Bush, Marco Rubio, Ben Carson, and Rand Paul on Thursday evening — but Walker faced the brunt of her fire. 

“It looks like he just gets his marching orders from the Koch brothers and just goes down the list,” she added.

Opening her speech, the Democratic front-runner recounted her time spent in Wisconsin while growing up in Chicago. “What happened?” she asked the crowd in feigned disbelief, implying that the state had declined.

“Scott Walker!” the riled up crowd responded, jeering.

Minutes later, the crowd again drowned her out after she started asking, “What happens when you’re a proud union member and your governor wants to—?"

The jabs came as some donors are urging Clinton’s campaign to start focusing her public appearances more on Bernie Sanders, her main opponent in the Democratic primary who has closed the gap in both Iowa and New Hampshire.

But Clinton’s campaign has pledged to keep her public focus on Republicans, and it followed through on Thursday.

Clinton’s first visit to the state was not lost on Walker, whose front-runner status in Iowa has recently slipped as Trump’s own star has risen.

“Hillary Clinton could learn a few lessons from the bold reforms we’ve enacted in Wisconsin since I took office,” he said in a statement on Thursday. “To move our country forward like we moved Wisconsin forward, we need a fresh face from outside Washington, D.C. to wreak havoc on the status quo and put hard-working American taxpayers back in charge. Hillary Clinton, who has been fighting for the ruling class over the working class for years, is not fit to take up that mantle."

He later responded to Clinton's speech with a series of tweets. 

"While you pander to union bosses, I give workers freedom to choose if they want to be in a union or not," he wrote. "The ONLY position that's extreme is not protecting life after 5 months."

Clinton’s speech here was always likely to be focused on Walker — Wisconsin is not an early-voting state, and it has voted for the Democratic presidential nominee in every election since 1984. And while Clinton has mentioned Bush and Rubio the most of any of her Republican rivals, Walker is often her third target, reflecting her campaign's belief that she might face him come November 2016.

So it was natural that her stop here would center on Walker, particularly given its status as a “Women for Hillary” event.

“Governor Walker has made it his personal mission to roll back women health and rights. He did defund Planned Parenthood, making it harder for some Wisconsin women to get those cancer screenings, those breast exams, that birth control, that life-saving preventative care. And he signed a dangerous ban on abortion after 20 weeks with no exceptions for victims of rape and incest,” said Clinton, who was introduced by Milwaukee Mayor Ted Barrett — loser of two straight governor’s races against Walker, in 2010 and 2012.

“Even though women in Wisconsin are still paid less than men, with women of color making even less, Scott Walker repealed protections for equal pay. Maybe he just doesn’t realize that when women are shortchanged, entire families are shortchanged, and Wisconsin and America are shortchanged."