The old political maxim goes that sincerity is the secret of success; once you can fake that, you’ve got it made. Well, Mitt Romney has a long way to go on the fake sincerity front. He may smile and frown at all the right places in debate, he may have mastered the Ronald Reagan diction, but the effect is not the tiniest bit real.

And that, I would suggest, was never more obvious than in the second Presidential debate of 2012.

SAUL LOEB/AFP/Getty

Mitt Romney and Barack Obama duel in the feisty second presidential debate at Hofstra University, New York.

We didn’t see it so clearly in the first debate, probably because we were distracted by the unaccountably disengaged performance of the man he is challenging, Barack Obama.

I don’t know about you, but I spent most of that first debate wondering about Obama. Was it some tactic, badly misjudged? Was he on medication? Did he just want to get back to Michelle, on their anniversary night? Was some national crisis of which we were unaware occupying his thoughts?

And sure enough, most of the media analysis and popular attention after the event was on Obama’s misfire. Even the performance of the host of the first debate, the hapless Jim Lehrer, was apparently subject to more analysis than Romney.

Anyway, it may forever remain a mystery where Obama went during the first Presidential debate, but the fact is today he was back.

He was animated, he was prepped, he was combative, and he made Romney look like the fake he is.

I don’t make this as a partisan point. All politicians gloss over the negatives and accentuate the positives, they all to some extent modify their message according to their audience. They are all selective with the truth. But can you think of one who is as sincerity-challenged as Romney?

Looking back over the more recent Republican Presidents. Reagan came across as genuine, or at least a peerless faker. George Bush senior was stiff and patrician, but genuine. George Bush the younger was genuinely dumb.

But Romney comes across as an entirely insincere product.

His ethos changes to suit the circumstance: the amoral ethos of the corporate raider who strips companies and offshores jobs, the moderate-liberal ethos of the governor of progressive Massachusetts, the Tea Party ethos for the Republican primary campaign, the exclusionary elitist of the fundraising circuit who disparages 47 per cent of the population, and the pretender to the middle ground now.

Lots of people have pointed out Romney’s contradictions; the odd thing about the first Presidential debate was that Obama let slip the chances to do it.

But not this time round. This time Obama got him, good. Time after time.

He got Romney on his attitudes to gun control. The governor, he noted had been in favour of a ban on assault weapons before he came out against it, while courting the endorsement of the National Rifle Association.

Romney had been a moderate on women’s reproductive rights until he had to appeal to the Tea Party.

When Romney promised to get tough on China, for taking American jobs, Obama whacked him for being one of those who invested in companies which exported jobs.

And when Romney tried to whack back, saying his investments were managed by a blind trust, and suggested Obama should look to the investments of his own pension plan, the President got the only decent laugh of the show, quipping that his pension was nowhere near as big or interesting.

When Romney attacked Obama over the decline in the coal industry, the President quoted back Romney’s words when, as Governor of Massachusetts he stood in front of a coal-fired power plant and said “this plant kills” and shut it down.

[For the record, the decline of the US coal industry is due to electricity generators switching from coal to gas, which is not only cleaner but now vastly cheaper.]

Obama tied Romney to the punitive policies of his party on immigration; he pegged him as more extreme on social policy than the Bush administration.

When a woman member of the audience asked the two men what they would do about equal pay for women, Obama pointed to his record in the Lilly Ledbetter case, in which the Supreme Court denied justice to a woman who had been systematically underpaid for years, compared with men doing the same work. A new fair pay act in her name was the first Act Obama signed into law.

Come Romney’s turn to respond, he talked about binders. When he became governor, he was distressed at the absence of women’s names among those potential appointees in the binders he was given. He asked for more. Women’s groups brought him “whole binders full of women”, he said. By the end of the debate, a Binders Full of Women Facebook page had 100,000 “likes” and was heading for 200,000 a few hours later. A Tumblr blog dedicated to a binder-based meme appeared instantaneously.

Other than that, his only answer was his generic one: more labour flexibility in a stronger economy.

Above all, Obama got him on the centrepiece of his pitch to voters: lower taxes.

He totted up the cost of Romney’s tax cut promises and got to USD8 trillion, to be mostly funded by closing tax loopholes. But, he noted, Romney had not itemised the loopholes, and had offered no other specific spending cuts “beyond Big Bird and eliminating funding for Planned Parenthood”.

[Big Bird being a reference to Romney’s promise to cut funds for public broadcasting.]

No-one who had seriously looked at Romney’s plan could find a way to make it add up, he said.

His attack was all the more effective for being unarguably right; no serious analysis can make the Romney maths work.

Now it must be said Romney had some powerful arguments going for him too, mostly related to the under-performance of the US economy on Obama’s watch.

But pointing out what’s wrong is not the same as offering a solution. Romney touted a “five point plan” of aspirations, but no hard maths.

And Obama derided it as really a one-point plan: looking after the rich folks with low taxes.

Given the state of things in America, you would normally expect an incumbent to lose, even to a challenger running on a policy of no more than “trust me”.

But this debate showed why this election remains so close, nonetheless.

You have one guy who clearly stands for what he believes, even if it has not worked as planned.

And another who stands for… what exactly?

Sincerity will decide it, I reckon.