Republican presidential hopeful and businessman Donald Trump speaks to the press following a rally on Saturday in Oskaloosa, Iowa. Getty Images

Presidential candidate Donald Trump slung mud at a new target while on the stump in Iowa: Wisconsin Gov. Scott Walker. Trump attacked Walker, one of whose fundraisers recently referred to the real estate tycoon as “DumbDumb,” for not taking care of his state, the Washington Post reported.

It took minutes for the mogul to set his sites on Walker, who leads in polls in Iowa. Trump Saturday blased his Republican challenger for allegedly mismanaging Wisconsin's budget, which over the next few years is projected to have a shortfall of more than $2 billion. Walker has been criticized for attempting to address the state's $283 million budget gap this year by cutting education funding and limiting the power of unions.

“Finally, I can attack!” Trump said, speaking at Oskaloosa High School, which is located about an hour outside of Des Moines. “Wisconsin’s doing terribly. It’s in turmoil. The roads are a disaster because they don’t have any money to rebuild them. They’re borrowing money like crazy. They projected a $1 billion surplus, and it turns out to be a deficit of $2.2 billion. The schools are a disaster. The hospitals and education was a disaster. And he [Walker] was totally in favor of Common Core, which I hate.”

Walker wasn’t the first to incur Trump’s wrath. His comments on two other leaders -- Sen. John McCain, R-Ariz., and Sen. Lindsey Graham, R-S.C. -- sparked controversy in recent weeks. He first said McCain, who spent years as a prisoner in Vietnam, was not a war hero. When Graham called Trump a “jackass” for the statement, Trump read out Graham's personal cell phone number at a campaign rally.

Though he’s proven to be outspoken and divisive, Trump is doing well in the polls. Numbers released Sunday by NBC News and Marist showed him leading the Republican presidential contest in New Hampshire. About 21 percent of GOP primary voters in the Granite State said they supported Trump. Former Florida Gov. Jeb Bush came in second with 14 percent; Walker, 12 percent.

But Walker maintained his advantage in Iowa where 19 percent of respondents said they backed him. With the support of 17 percent, Trump was No. 2 -- a position he addressed in Saturday's speech, the Hill reported.

“I can’t believe I’m in second place,” he said. “Folks, will you please put me in first place so I feel better?”