Donald Trump was booed by the crowd at the Republican presidential debate after blaming George Bush for the destruction of the twin towers on 11 September 2001.
The party front-runner’s attack on the former Republican president was the most controversial moment in the CBS broadcast, which was laced with more aggression and venom than any of the previous debates.
Despite his comfortable lead in the polls and a pledge to conduct himself in a more statesmanlike manner, the billionaire tycoon launched volleys of insults at rivals Jeb Bush and Ted Cruz. Meanwhile, Cruz scuffled with Marco Rubio over immigration.
But as ever, it was Trump who provoked the biggest reaction from the Greenville, South Carolina audience. “How did he keep us safe when the World Trade Center went down?” he asked, his comments quickly drowned by a rising chorus of catcalls.
Donald Trump: "The World Trade Center came down during the reign of George Bush. He kept us safe? That is not safe." pic.twitter.com/3KS9h1BJjA— POLITICO (@politico) February 14, 2016
I lost hundreds of friends,” Trump continued, raising a hand and pausing to ask the crowd to let him continue speaking. “The World Trade Center went down during the reign of George Bush. He kept us safe? That is not safe."
Despite the crowd’s hostility, Trump looks set to triumph in the South Carolina Republican Primary on Saturday 20 February. He is currently polling at around 35%, 20 points clear of his nearest rivals Cruz and Rubio.
The former Apprentice star managed to keep his composure as the Presidential candidates paid their tributes to Supreme Court Justice Antonin Scalia, who was found dead at his Texan ranch on Saturday.
The candidates bowed their heads for a moment’s silence in memory of the Republican grandee, before discussing whether Barack Obama would be able to appoint a Democratic judge before he left office.
If he is successful, the move could significantly alter the political tenor of the highest American court, which currently leans to the right. Trump called on Republican senators to “delay, delay, delay” the appointment proceedings until he or another Republican could make the appointment.
But after George Bush’s younger brother Jeb took a potshot at Trump for his support of Russian intervention in Syria, Trump fired back with typical bombast, describing the launch of the Iraq war as "a big, fat mistake."
"George Bush made a mistake," he continued, his face red with exertion. "We all make mistakes. But that one was a beauty ... They lied. They said there were weapons of mass destruction. And there were none."
When the crowd booed him for his comments about 9/11, Trump dismissed them as “lobbyists and special interests.”
He has previously been criticised for claiming to have seen “thousands” of people celebrating in the streets following the terrorist attacks in which 3000 Americans lost their lives.
Donald Trump's most controversial quotes
Donald Trump's most controversial quotes
1/14 On Isis:
"Some of the candidates, they went in and didn’t know the air conditioner didn’t work and sweated like dogs, and they didn’t know the room was too big because they didn’t have anybody there. How are they going to beat ISIS?"
2/14 On immigration:
"I will build a great wall — and nobody builds walls better than me, believe me —and I’ll build them very inexpensively. I will build a great, great wall on our southern border, and I will make Mexico pay for that wall. Mark my words."
3/14 On Free Trade:
"Free trade is terrible. Free trade can be wonderful if you have smart people. But we have stupid people."
PAUL J. RICHARDS | AFP | Getty Images
4/14 On Mexicans:
"When Mexico sends its people, they’re not sending their best. They’re sending people that have lots of problems. They’re bringing drugs. They’re bringing crime. They’re rapists."
5/14 On China:
"I just sold an apartment for $15 million to somebody from China. Am I supposed to dislike them?... I love China. The biggest bank in the world is from China. You know where their United States headquarters is located? In this building, in Trump Tower."
6/14 On work:
"If you're interested in 'balancing' work and pleasure, stop trying to balance them. Instead make your work more pleasurable."
7/14 On success:
"What separates the winners from the losers is how a person reacts to each new twist of fate."
8/14 On life:
"Everything in life is luck."
9/14 On ambition:
"You have to think anyway, so why not think big?"
10/14 On his opponents:
"Bush is totally in favour of Common Core. I don't see how he can possibly get the nomination. He's weak on immigration. He's in favour of Common Core. How the hell can you vote for this guy? You just can't do it."
11/14 On Obamacare:
"You have to be hit by a tractor, literally, a tractor, to use it, because the deductibles are so high. It's virtually useless. And remember the $5 billion web site?... I have so many web sites, I have them all over the place. I hire people, they do a web site. It costs me $3."
12/14 On Barack Obama:
"Obama is going to be out playing golf. He might be on one of my courses. I would invite him. I have the best courses in the world. I have one right next to the White House."
13/14 On himself:
"Love him or hate him, Trump is a man who is certain about what he wants and sets out to get it, no holds barred. Women find his power almost as much of a turn-on as his money."
14/14 On America:
"The American Dream is dead. But if I get elected president I will bring it back bigger and better and stronger than ever before and we will make America great again."
When Bush bought up Trump’s previous criticism of his 90-year-old mother, Trump joked: “she should be running.”
Cruz was dubbed “the biggest liar” and “a nasty guy” after questioning Trump’s conservative credentials. Cruz also shut down Marco Rubio’s accusation that he couldn’t speak Spanish by replying to Rubio in Spanish.
Calls for unity and harmony by Ben Carson and John Kasich were ignored throughout the acrimonious two-hour debate, for which Trump once more set the tone.
And Trump’s headline-grabbing style continues to pay dividends. He cornered 40% of Twitter mentions during the debate, far more than any of the other candidates.