Ben Carson answered Donald Trump's highly personal attack on Friday by saying he won't get into the "mud" and engage in the "politics of personal destruction."
The retired neurosurgeon addressed Trump's extensive remarks -- in which the billionaire businessman likened Carson's story about pathological anger to a "child molester" mentality and asked how "stupid" voters are to believe Carson's personal narrative -- during a campaign stop in Greenville, S.C.
"I expect that kind of thing," Carson said.
Of Iowa caucus-goers, he said they'll be able to make a decision about whether they want to listen to the "usual politics of personal destruction."
He suggested political trends are dragging the country "into the mud," but added:
"I don't have to get into it."
Trump's speech Thursday night in Iowa was stunning even by Trump standards, and marked a departure from his reserved demeanor during this week's debate. Using coarse language, Trump trained his criticism on co-front-runner Carson while taking shots at several others.
Striking was a comparison between Carson's "pathological temper" and the mindset of child molesters.
"If you're pathological -- there's no cure for that, folks. Okay? There's no cure for that," Trump said at the rally in Fort Dodge, Iowa.
He then referenced comments he made earlier on CNN: "I said that if you're a child molester -- a sick puppy -- you're a child molester, there's no cure for that."
After questioning the retired neurosurgeon's story of how he nearly stabbed a friend during his adolescence, Trump also bellowed, "How stupid are the people of Iowa? How stupid are the people of this country to believe this crap?"
GOP rival and former HP CEO Carly Fiorina shot back on Facebook and jumped to Carson's defense, writing:
"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."
South Carolina Sen. Lindsey Graham also told Fox News he's thinks the speech marked a "turning point" in the race.
"I think he melted down last night," Graham said Friday. "What he said about Dr. Carson ... Dr. Carson found redemption in the Lord. He is a good and decent man."
Speaking on Fox News shortly afterward, Trump spokeswoman Katrina Pierson cited Graham's low poll numbers and said she wasn't sure his criticism "warrants a response." But she defended Trump's comments on Carson.
"A lot of people are having a hard time understanding what's revolving around Dr. Ben Carson," she said.
Referring to the use of the term "pathological," she said, "The most common pathology used in terms of health care is unfortunately child molestation." However, she said, Trump "was not calling Ben Carson a child molester."
Trump has been trading the lead in polls with Carson for the past several weeks. He's also built a strong following while routinely insulting his opponents, on a personal level, since the start of the campaign -- and in defiance of past pundit predictions that he'd gone too far with various off-color comments.
But Thursday's remarks appeared to hit a new level.
He also acted out the stabbing scene, lurching forward and moving his belt up and down and shouting, "but, lo and behold, it hit the belt!"
Pierson said the "stupid" remarks were "tongue in cheek." "He wasn't calling people stupid in general," she said.
In his free-wheeling appearance, Trump also said Florida Sen. Marco Rubio, who is rising in the polls, was "weak like a baby, like a baby" and "not a good poker player because every time he's under pressure he starts to just profusely sweat." And he said former Florida Gov. Jeb Bush didn't deserve his attention because his campaign is doing so poorly.
Carson's ability to overcome his anger as well as an impoverished childhood to become a world-renowned neurosurgeon has been a central chapter in his personal story.
In his book "Gifted Hands," Carson described the uncontrollable anger he felt at times while growing up in inner-city Detroit. He wrote that on one occasion he nearly punched his mother and on another he attempted to stab a friend with a knife.
"I had what I only can label a pathological temper - a disease - and this sickness controlled me, making me totally irrational," Carson said in describing the incident with his mother. He referred to "pathological anger" again in telling about lunging at his friend, the knife blade breaking off when it hit the boy's belt buckle.
Carson describes in "Gifted Hands" racing to the bathroom in his house after the near-stabbing incident and in time began to pray for God's help in dealing with his temper. "During those hours alone in the bathroom, something happened to me," he wrote. "God heard my deep cries of anguish. A feeling of lightness flowed over me, and I knew a change of heart had taken place. I felt different. I was different."
In questioning Carson's religious awakening, Trump said in Fort Dodge that Carson went into the bathroom and came out and "now he's religious."
"And the people of Iowa believe him. Give me a break. Give me a break. It doesn't happen that way," he said. "Don't be fools."
The Associated Press contributed to this report.