Donald Trump: "Will you get the numbers up, Iowa, please?"

It was uncharted territory for a noticeably somber business mogul Donald Trump in Sioux City, Iowa on Tuesday evening. He was delivering his first speech in the state since a spate of polls showed him slipping behind retired neurosurgeon Dr. Ben Carson in Iowa, which holds the first voting contest in the country next year.

"Will you get the numbers up, Iowa, please?" Trump beseeched more than 2,000 supporters at West High School. "This is ridiculous!"

This time, Trump, whose unscripted verbal barrages on the stump have consisted mostly of his reciting high poll numbers and criticizing the political establishment, seemed distinctly aware of his second-place status. A new CBS poll released Tuesday showed Carson pulling ahead nationally as well.

Trump targeted Carson a number of times throughout the speech. He dinged Carson for endorsing a flat tax in which everyone would pay taxes, while his own plan, he said, would exempt some 40 percent of the U.S. He also claimed that Carson wanted to abolish Medicare.

The biggest criticism of Carson came in a lengthy riff critical of super PACs. Trump seemed to conflate Carson's official campaign finance report and that of his aligned super PAC by implying that Carson had blown through his cash on hand. Trump accused Carson of spending 70 to 80 cents on the dollar to raise money. Carson has more than $11 million cash on hand and raised $20 million in the last quarter. Carson also spent $14 million in the quarter.

Then Trump moved on to Carson's Super PAC, referring to it as a "horrible, horrible scam."

"Now, in Ben's case, his super PAC is running Iowa, and let me tell you, the people who are running that super PAC, even if it comes in small donations, those are the real bosses. Those are the bosses."

This was also Trump's first trip back to Iowa since his account retweeted an insult to the mental capacity of Iowa voters after a state poll came out showing Carson ahead. Trump later blamed the tweet on an intern.

On Tuesday evening, Trump was a little more measured - and spent more time sounding like a traditional politician. He took questions after the speech -- something he rarely does in Iowa -- and spent extended time on the rope line. He also spent less time talking about his polls and more about policy.

Trump was quizzed on Israel ("We will support Israel 1000 percent!"), and Social Security. And a veteran asked what he would do to reform the Department of Veterans Affairs. Trump took the time to step off the podium and shake his hand and meet his family.

One supporter told Trump that she was excited to see Melania put "class back in the First Lady."

Trump's slide in the Iowa polls wasn't a surprise to some Iowans, even ardent supporters.

"I expected it," said 68-year-old Wally Hamann, a retired tire store manager. "He's a little too Eastern United States for Iowans. A little too abrupt. They like nice people, like Ben Carson - who's a super guy."

Trump's rally also attracted hundreds of protesters, mostly Hispanic, who had gathered outside to demonstrate against both Trump and the school for allowing Trump to speak.

Many of the protesters said they attended the school or one of the surrounding high schools. They said that Hispanic students in the school were being bullied as a result of objecting to Trump's speech there.

One protest organizer, 24-year-old Ismael Valabez from South Sioux City, Nebraska, said, "Basically, we believe that these types of events shouldn't be held at the school. We believe it violates our anti-bullying policy."

Valabez says he has family members that attend the school, including a niece who said someone at the school had called her an illegal immigrant.

"Donald Trump coming here has aggravated a lot of tensions in the school that has a lot of Hispanic students in it and a lot of white students in it. It's created a divide in the student body," said Caroline Johannes, who is half Puerto Rican, said. Johannes doesn't have any relatives in the school, but came to the event anyway, to support the community.