WASHINGTON — Donald Trump compared Ben Carson to a child molester, accusing him of harboring “pathological’’ anger. He called Marco Rubio “weak like a baby.” He dismissed Carly Fiorina as “Carly whatever-the-hell-her-name-is.”
And then, standing on a stage in Fort Dodge, Iowa, he called out, “How stupid are the people of Iowa?”
In a presidential campaign chock full of over-the-top rhetoric, the billionaire casino and hotel mogul further raised the stakes on his bullying and name-calling in a 95-minute performance Thursday night that drew another explosion of media attention and accompanying scorn.
He even pantomimed stabbing motions, ridiculing a story that Carson tells of his troubled youth in Detroit.
As a backlash built Friday, some observers said Trump may have finally gone too far, hurting his standing at the top of most polls and also adding to worries among Republicans about their field this season.
In the eyes of some, Trump is undermining efforts by Republican leaders to prove the party is prepared to nominate a serious candidate who can mount a credible campaign against the likely Democratic nominee, Hillary Clinton.
But Trump himself doubled down, sending out a video on Friday that again attacked Carson. Carson poses the biggest threat to Trump’s dominance in the large primary field and has recently eclipsed Trump in some polls.
‘‘Violent criminal? Or pathological liar?’’ the video asks. ‘‘We don’t need either as president.’’
Carson, in response Friday, presented himself as taking the high road.
“Pray for him,” Carson said in response to Trump’s barrage, according to one of his advisers.
“You would know something about pathological,” Fiorina said of Trump.
Trump remains the front-runner for the Republican nomination in national polls, a perch he has held for months despite similar outbursts of politically incorrect language. Republican Party officials have grown increasingly worried that he is becoming their most visible spokesman and harming their chances of attracting women, Hispanics, and black voters.
The party reduced the number of debates in the 2016 primary campaign as a way to select a more electable front-runner early and to prevent the eventual nominee from getting caught in verbal snafus that could hurt it in a general election.
“To be president, you have to be rational, you have to have a decision-making process, and you have to have a certain level of discipline,” said Scott Reed, who managed Bob Dole’s 1996 presidential campaign and is now the senior political strategist at the US Chamber of Commerce. “What we saw in Iowa was eye-popping. I really believe it’s the beginning of the end.
“I’m going to stick with my prediction: He will be out before the Iowa caucus. Because he does not want to lose, he does not want to be a loser, and he’s not going to win Iowa.”
But Trump’s demise has been predicted numerous times already in this campaign — after he kicked things off by calling Mexican immigrants “rapists’’ in his announcement speech, when he insinuated that an aggressive Fox news debate moderator was menstruating, and by suggesting in Rolling Stone magazine that Fiorina is unattractive: “Look at that face.’’ Those are just the most prominent examples.
“On the one hand, Trump isn’t helpful,” said Stuart Stevens, a longtime Republican consultant who helped run Mitt Romney’s 2012 campaign. “On the other hand, if Trump is rejected, that is helpful. We’re in a state where Trump isn’t helpful. But I think he’ll be rejected. And I think that will be helpful.
“Trump’s an unstable character,” Stevens said. “Analyzing him is like analyzing Mike Tyson’s view of the world. I just don’t think it’s very productive or interesting. He’s unstable. He’s uninformed. And he has a microphone. That’s rarely a good combination.”
Some have even floated Romney getting in the race, although it’s a prospect that seems unlikely.
“It’s naturally an inevitable that people would like Mitt Romney to be running,” Stevens said. “I think if he was running, he’d be winning. It’s hard not to look at these debates and think Mitt Romney would dominate them.”
But if Romney wanted to be running, Stevens said, he would be in the race.
Some Iowans have been reacting to Trump’s insults with laughter.
“It’s not necessarily outrage,” said Craig Robinson, a former political director for the Iowa Republican Party. “It’s more ‘can you believe this?’ type of deal.”
The only thing predictable about Trump has been his unconventional — some would say bizarre — approach to running for president. On Thursday as other candidates, such as Rubio and Ted Cruz, were arguing about an issue Trump has pushed — immigration — Trump launched his news-grabbing round of personal attacks.
“To me, I see a lot of missed opportunities with Trump more than anything,” Robinson said. “Yesterday, we’re in the midst of this Rubio-Cruz fight on his key issue: immigration. Instead he focuses on Ben Carson. I don’t get it.’’
“People are really perplexed by his comments,” said Jeff Jorgensen, chairman of the Pottawatomie County Republicans in Iowa.
“But I don’t think it’s going to hurt Trump, per se. He’s got a pretty strong following, and Trump is supposedly stepped in it quite a few times but it hasn’t put a nail in his coffin. I don’t think this is going to do it either.”
Trump on Thursday night repeatedly questioned Carson’s inspirational life story, saying that some of the core aspects were untrue. He suggested Carson’s story about converting to Christianity was made up (“He goes into the bathroom for a couple of hours and he comes out and now he’s religious. . . . Give me a break”).
Trump also called ridiculous Carson’s claim to have attempted to stab someone only to have been blocked by the person’s belt buckle.
“So I have a belt: Somebody hits me with a knife, it’s going in because the belt moves this way. It moves this way, it moves that way,” Trump said, flipping his belt buckle as the crowd chuckled. “He hit the belt buckle. Anybody have a knife? Want to try it on me? Believe me, it ain’t gonna work.”
Trump continued saying that Carson has a “pathological disease,” a reference to a passage in Carson’s book in which he writes that as a child he had a “pathological temper.”
“A child molester, there’s no cure for that,” Trump said. “If you’re a child molester, there’s no cure. They can’t stop you. Pathological? There’s no cure.”
“It’s not the kind of dialogue that I would ever engage in,” Carson told reporters in South Carolina on Friday.
He also attempted to give Trump a vocabulary lesson.
“I’m hopeful maybe his advisers will help him to understand the word pathological and recognize that that does not denote incurable,” Carson said. “It’s not the same.
“It simply is an adjective that describes something that is highly abnormal. And something that, fortunately, I have been able to be delivered from for half a century.”
Matt Viser can be reached at matt.viser