Donald Trump on Ben Carson Stories: 'How Stupid Are the People of Iowa to Believe This Crap'

— -- On a contentious day in the GOP race, frontrunner Donald Trump didn't shy away from calling out his rival "in second place" Ben Carson, asking the 1,500 Iowans in the crowd today about Carson's "pathological stories" in his book and saying "How stupid are the people of Iowa to believe this crap?"

Trump focused on a story from Carson's books where he writes about stabbing someone with a knife.

"It hit the belt. And the knife broke. Give me a break," Trump told the crowd at Iowa Central Community College. Trump then stepped away from the podium and demonstrated what Carson stabbing a friend in the belt would look like.

"He hit the belt buckle? Anybody with a knife wanna try it on me? Believe me it ain't gonna work," Trump said.

After attacking the people of Iowa for supporting Carson, Trump said he loves the people here, noting, "I think I'm going to buy a farm and move here.”

But, Ben Carson wasn't the only focus of the night as Trump touched on a handful of issues, from bombing ISIS to Mitt Romney's loss and Tuesday's GOP debate on Fox Business.

Trump said Carly "whatever her name" Fiorina needs to go for constantly interrupting. Fiorina's team emailed out this response Thursday night saying, "Donald, sorry, I've got to interrupt again. You would know something about pathological. How was that meeting with Putin? Or Wharton? Or your self funded campaign? Anyone can turn a multi-million dollar inheritance into more money, but all the money in the world won't make you as smart as Ben Carson."

In reference to Karl Rove's op-ed in the Wall Street Journal, Trump said, "what a dope this guy is. This dope spent $435 million last cycle, didn't win one race and I saw some of the ads, I thought they were so bad, I thought they were made by the Democrats."

Shifting back to his fellow GOP candidates, Trump said Ohio Gov. John Kasich gave him a "massive headache" at the debate. The billionaire also said Bush and Rubio can't do the job, sarcastically saying, "You can put Jeb in there. This lightweight Marco Rubio in here. He's a lightweight, put him there."

Trump even went after former New York Gov. George Pataki, saying, "he couldn't have been elected dog catcher. He didn't even make the child's stage two days go."

Clearly feeling fired up about his status at the top of the polls, Trump cursed during his remarks when telling the crowd how he would handle ISIS in the Iraqi oil fields saying he would "bomb the sh**" out of them.

The night began with Donald Trump talking about the GOP race in general terms acknowledging that "people are getting a little rambunctious." But, in the end it was Trump who really took the gloves off.