Almost lost, at times, were the town-hall participants who were supposed to play a major role in asking questions. The candidates got in each other's space and spoke over each other's lines. "You'll get your chance. I'm still speaking," Romney said at one point as the audience gasped.

"I'm the president," Obama said when asked about the recent deadly attack on Americans in Libya. Pointing at Romney, he said the suggestion that anyone on his team "would play politics or mislead when we've lost four of our own, governor, is offensive. That's not what we do".

The Libya discussion provided the night's most dramatic moment and scored a big point for Obama, whose handling of the issue has been widely panned by his opponents. Obama said in his own defence he had declared the Benghazi assault an "act of terror" the day after it took place.

Sensing a mistake, Romney went in for the kill. "I think it's interesting, the president just said something, which is that on the day after the attack he went into the Rose Garden and said that this was an act of terror."

"That's what I said," Obama replied.

"You said in the Rose Garden the day after the attack, it was an act of terror? It was not a spontaneous demonstration, is that what you're saying?" Romney persisted.

"I want to make sure we get that for the record - because it took the president 14 days before he called the attack in Benghazi an act of terror."

"Get the transcript," Obama suggested. As Romney stood centre stage, looking less sure of himself, CNN journalist and debate moderator Candy Crowley stepped in: "He did in fact, sir."

"Can you say that a little louder, Candy?" Obama asked with amusement. "He, he did call it an act of terror," she stuttered, as Romney looked deflated.

In fact, on September 12, in the Rose Garden, Obama had indeed said in reference to the Benghazi attack: "No acts of terror will ever shake the resolve of this great nation."

With China policy emerging as a key issue in the race for the White House, Obama mocked his foe's record of making money on overseas investments while Romney countered that the Democratic incumbent has been soft on Beijing.

"Governor, you're the last person who's going to get tough on China," Obama said after Romney repeated his promise to crack down on Beijing over its widely criticised trade practices and currency policy.

"When he talks about getting tough on China, keep in mind that Governor Romney invested in companies that were pioneers of outsourcing to China, and is currently investing in companies that are building surveillance equipment for China to spy on its own folks," Obama said.

Obama's aggressive response may have referred to an article in that laid out how Bain Capital, the private equity firm founded by Romney, was profiting from investments in Chinese companies.

Romney made a point of returning to the issue of China multiple times during the debate.

"China has been a currency manipulator for years and years," Romney said, lambasting Obama for not labelling Beijing as such.

"On day one, I will label China a currency manipulator. We'll make sure people we trade with around the world play by the rules." Obama fired back, saying the yuan had appreciated during his time in office "because we have pushed them hard."

Responding to the comments in the debate, Foreign Ministry spokesman Hong Lei said Beijing does not manipulate its currency, and said the US presidential candidates should view China in a fair and objective way.

Chinese development is important for the US and the two sides have broad interests and responsibilities, Hong said.

As if to put a bookend on his second debate performance, Obama chose his last minutes to mention what he never did last time, Romney's caught-on-tape statement that nearly half the people of the nation "believe that they are victims".

"Think about who he was talking about," the president said in an appeal to the middle-class voters at the centre of the entire campaign.

The burden, the anticipation, the opportunity — it all focused on Romney in the first debate because he was trailing and needing a breakthrough. This time, undecided voters needed to hear from Obama why they will be better off if they rehire him.

That's exactly what one of the questioners, Michael Jones, asked Obama after saying he had voted for him last time. Obama recited all he has done - helping the vehicle industry, cutting taxes, tracking down Osama bin Laden - and then pivoted to his next economic plan.

Romney's response to Jones: "I think you know better. I think you know that these last four years haven't been so good as the president just described and that you don't feel like you're confident that the next four years are going to be much better, either."

It spoke to Romney's approach this time: stay aggressive but pull everything back to the theme that Obama has been a disappointment in the way that matters most to people, their economic security.

The third and final debate is scheduled for Monday.

What they said...
 

NOT READY FOR COMMAND

Obama While we were still dealing with our diplomats being threatened, Governor Romney put out a press release, trying to make political points, and that's not how a commander-in-chief operates.
 

THE GREAT UNRAVELLING

Romney The president's policies throughout the Middle East began with an apology tour, and he pursued a strategy of leading from behind, and this strategy is unravelling before our very eyes.
 

OPEN DOOR POLICY

Romney This is a nation of immigrants. We welcome people … as immigrants. My dad was born in Mexico of American parents; Ann's dad was born in Wales and is a first-generation American.

Obama We are a nation of immigrants. I mean we're just a few miles away from Ellis Island. We all understand what this country has become because talent from all around the world wants to come here.
 

PENSIONING HIM OFF

Romney Have you looked at your pension?

Obama I don't look at my pension. It's not as big as yours.
 

HE SAID WHAT? WHEN?

Romney I want to make sure we get that for the record. It took the president 14 days before he called it an act of terror.

Obama Get the transcript.

Moderator Candy Crowley He did, in fact, call it an act of terror.

Obama Could you say that a little louder, Candy?
 

THAT'S NOT ME

Obama A lot of this campaign has been devoted to this notion I think government creates jobs. That's not what I believe … the free enterprise system is the greatest engine of prosperity the world has ever known.

Romney The president's campaign tried to characterise me as someone that is very different than who I am. I care about 100 per cent of the American people. I care about our kids.
 

ENTER THE DRAGON

Romney China's been a currency manipulator for years … and the president has a regular opportunity to label them as a currency manipulator, but refuses to do so. Day one, I'll label China a currency manipulator.

Obama Governor, you're the last person who's going to get tough on China. Keep in mind that Governor Romney invested in companies that were pioneers of outsourcing to China, and is currently investing in companies that are building surveillance equipment for China to spy on its own folks.