Donald Trump – centre stage once again – dishing it out and taking hits from all comers.

He opened the second debate saying Rand Paul did not deserve to be there as number 11. Mr Paul scoffed.

It was not long before Mr Trump was confronted by his own words about the only female Republican candidate Carly Fiorina.

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Last week he said of her face: “Would anyone vote for that?”

On Thursday Ms Fiorina said: “I think women all over this country heard very clearly what Mr Trump said.”

She got 12 seconds of raucous applause.

Mr Trump followed up with “I think she’s got a beautiful face and I think she’s a beautiful woman”. The room was silent.

The billionaire businessman also clashed with Jeb Bush, who he has accused of being soft of immigration because his wife is from Mexico.

Mr Bush demanded he apologise to her. Mr Trump refused, saying he did not say anything wrong.

Ms Fiorina and Mr Trump clashed again talking about how successful they have been in business.

New Jersey governor Chris Christie interrupted them: “You’re both successful people, congratulations, but the 55-year-old construction worker watching doesn’t care.”

The candidates were tested on their knowledge of issues over three hours – foreign policy, the economy, immigration.

Trump, Fiorina and Bush hold the spotlight

Few took the spotlight off Mr Trump except Mr Bush and Ms Fiorina.

Ohio governor John Kasich tried with his positive outlook and decision not to attack Hillary Clinton.

Former second-placed in the polls Wisconsin governor Scott Walker tried by attacking Mr Trump.

“Mr Trump, we don’t need an apprentice in the White House, we have one right now,” he said.

Former brain surgeon Dr Ben Carson, who is currently running second in the polls, educated Mr Trump about vaccines and autism.

He also tried to cast himself as the outsider candidate.

“Politicians do things that are politically expedient. That is not the reason that I have gotten into this thing,” he said.

But ultimately it was about Mr Trump again.

He attacked Mr Bush recently for being low energy.

When asked what Secret Service code name he would like former governor Mr Bush said “Eveready”, as in the battery.

Even Mr Trump laughed – they actually hand slapped. The Donald said his code name would be “Humble”.

He isn’t, he won’t be and despite his opening remark that he’s not being “braggadocious” Mr Trump just felt he wasn’t up to answering anyone’s questions or conceding he may not be right.

Throughout the entire three hours the closest he came to being humble was by saying he has a lot to learn about foreign policy, but that’s because he is so busy doing deals.

Awwwwkward https://t.co/bgmvNFo3HC #CNNDebate

— Michael Rusch (@weeddude) September 17, 2015

.@CarlyFiorina surprised many when asked which woman should appear on $10bill. #CNNDebatehttp://t.co/hO0HJcL54dhttp://t.co/H3nXOhdQEy — The Situation Room (@CNNSitRoom) September 17, 2015

-ABC