Presidential contender Donald Trump has come under attack at a Republican debate, hours after being hammered by some of the party’s veteran politicians.
The front-runner in the race to be the party’s nominee took to the stage in Detroit with rivals Marco Rubio and Ted Cruz keen to make their mark.
Mr Rubio said Mr Trump deserved to be attacked because he had mocked others.
Many Republicans fear Mr Trump would lose November’s presidential election.
The debate hosted by Fox News began with Mr Trump being asked about an attack earlier in the day by Mitt Romney, the 2012 nominee, who accused the businessman of bullying, greed and misogyny.
Calling him a “phony” and a “fraud”, the former standard-bearer of the party said Mr Trump’s policies – like the deportation of undocumented migrants and banning Muslims from entering the US – would make the world less safe.
On the debate stage, Mr Trump dismissed the criticism because Mr Romney was a “failed candidate”, but he immediately found himself on the defensive from Mr Rubio.
The Florida senator said he was “not going to turn over the conservative movement to someone who thinks the nuclear triad is a rock band from the 1980s”.
Other debate highlights:
- Mr Rubio challenged Mr Trump on outsourcing his clothes line to China and Mexico
- The businessman promised to move clothing manufacturing back to the US
- Mr Cruz said Mr Trump has been part of the corruption in Washington that his supporters are angry about
- The Texas senator also said Mr Trump wrote four cheques to get Clinton elected in 2008
- Ohio Governor John Kasich said he was the “grown-up” on the stage who had the best chance against Democrat Hillary Clinton
- Using a big screen with graphics, Fox host Chris Wallace challenged Mr Trump on whether his planned savings added up
In one of the most bizarre moments, Mr Trump defended the size of his hands and then quipped about another part of his anatomy.
There were plenty of personal insults from Mr Trump, who labelled one rival “little Rubio” and another “liar Ted”.
The New York businessman was on the defensive about a civil lawsuit involving the collapse of Trump University.
And he was challenged by the Fox News panel for changing his stance on Syrian refugees, the war in Afghanistan and President George W Bush.
He replied: “I have a very strong core. But I’ve never seen a successful person who wasn’t flexible, who didn’t have a certain degree of flexibility.”
As well as Mr Romney, other senior Republicans like Paul Ryan, John McCain and a host of national security committee members have also attacked the New Yorker since he cemented his front-runner status on Super Tuesday.
Mr Trump, a billionaire with no experience of political office, has won 10 of the 15 states that have voted so far, with his promise to “make America great again”.
Europe hates Trump – Analysis by the BBC’s Katty Kay
When it comes to Trump, Europe is apoplectic. Fascinated, but appalled.
I’m sometimes asked by Americans what Brits make of Trump and the best analogy I can come up with is this:
Imagine if your much-respected but slightly annoying older sibling (the US) came home with a fantastically unsuitable date (Trump).
Part of you is titillated but part of you is appalled, thinking “oh my God, this could go horribly wrong”
Europe hates Trump – read Katty’s article in full
With the effective departure of Ben Carson this week, the field of Republican candidates – once 17-strong – has now been narrowed to four.
On Thursday morning, Mr Trump predicted he would be assailed from all sides in the debate.
“I can’t act overly presidential because I’m going to have people attacking from every side,” he told NBC.
The debate, sponsored by Fox News, is the first time Mr Trump has faced his rivals since winning seven states on Super Tuesday.
It also brought him face to face with presenter Megyn Kelly, whom he dismissed as a “bimbo” after they clashed in the first primary debate.
This time he was all smiles and he complimented her looks when he took her first question.
In the Democratic race, Hillary Clinton has 10 states, five more than rival Bernie Sanders.
The two will take to the debate stage in Flint, Michigan, on Sunday.