JEB BUSH: The former Florida governor brought slightly more energy to the debate, and was clearly one of the candidates who had decided the best way to counter Donald Trump's rise in support was to go on the offensive. He was quick to defend his brother, former President George W Bush, when under attack, and defended his Mexican-born wife after she was dragged into the immigration debate. With his money and connections he remains a player but has to start moving up the polls or backers will get nervous. 6/10

BEN CARSON: A solid performance in the first debate brought good poll numbers, but he still seems detached and lacking in experience. He disappeared for long periods of the almost three-hour long debate. It will be interesting to see if people are beginning to look elsewhere for a candidate to win the White House. 5/10

CHRIS CHRISTIE: Took a while to make an impact but he timed it right. He intervened in a battle over Trump and Fiorina's business record to remind them they should be thinking about middle class America and the economy. That would have gone down well with voters at home. Keeps repeating how George Bush made him a US district attorney on September 10, 2001. That is not true and at some point a moderator is going to pin him down on that. 6/10

TED CRUZ: Gave the answers his conservative base want to hear but didn't really seize the opportunity to expand his support. The fact he did not attack other Republicans will go down well with voters. His famous debating skills gets lost with so many others on the stage. 5/10

CARLY FIORINA: The former computer company executive was in the minor debate first time around, but her performance saw her poll numbers shoot up and she gained a place on the main stage this time. She did not waste the opportunity. She wasn't scared to attack Donald Trump, push her own personal story and vigorously defend her business record when under attack. Will only see her poll numbers increase on the back of this. The performance of the night. 9/10

MIKE HUCKABEE: Trying to catch lightning in a bottle again. Won the Iowa caucuses eight years ago and appeals to a small section of the party base. Was largely anonymous last night and got perhaps least time of anyone on stage. His stance on social issues does not really reflect where America is at the moment. An important voice but a diminishing presence. 3/10

JOHN KASICH: The Ohio governor won't attack his fellow Republicans, tries to remain statesmanlike and reminds everyone the Iran deal was agreed with friends and allies and so is not easily junked. He will appeal to the centre and could attract support from Democrats. That makes him electable. And the Republicans really want someone who can win the White House. If his poll numbers keep going up, he will attract big money support. 6/10

RAND PAUL: Will have appealed to his Libertarian base support but will have done little to convince other voters he is the man who can win the White House. He attacked Trump but then failed to pivot to show his own strengths a basic requirement in this forum. Poor night. 3/10

MARCO RUBIO: Smart enough to turn every opportunity to speak to reiterate his personal story [so voters can get to know him] or to praise American exceptionalism. The Florida senator appeals to the Latino vote, which the Republicans need to grow. And managed to slap Donald Trump down without making it look like an attack. Will still have to square his position on immigration with previous statements but is perhaps everyone's second favourite candidate. 8/10

DONALD TRUMP: Did not shine like he did in the first debate and came under attack from the others on the stage. Perhaps is learning he needs real policies and cannot keep saying everything is going to be wonderful. Has built up enough goodwill and support that it won't evaporate overnight - but the Trump bubble has definitely burst. 5/10

SCOTT WALKER: Arguably the night's biggest loser. From being a front-runner, his campaign story has been one of decline. He is dropping in the polls and he needed a big moment to grab attention and reassert himself. It didn't happen. Had one good line attacking Trump, but he needs more than that. Will spend the next few days reassuring donors and supporters he can turn things around. 4/10

Source: Al Jazeera