President Obama (delivering the graduation speech at Barnard College, New York) has chosen to fight the Republicans on the culture war front 

The outline of how the presidential elections are going to be fought is becoming much clearer, and for President Obama the answer seems to be an inversion of "It's the economy, stupid", the phrase coined by Clinton campaign strategist James Carville to explain why his man was a better choice than George H.W. Bush in 1992. While the Republican challenger Mitt Romney concentrates on the single area where he consistently outpolls Obama — economic competence — the President is opening up flanks in America's culture wars that wrong-foot the Republicans at every turn. Obama's may well be a winning strategy, unless Carville's line for 1992 holds for all American elections.

With unemployment stubbornly staying above 8 per cent, the eurozone crisis damaging American exports, a $15.56 trillion national debt continuing to grow, much of the housing market still floundering in negative equity and home ownership at its lowest level since 1965, it's understandable if Obama prefers to shift the focus onto those social and personal areas where he regularly beats Romney. His commencement address at the all-women Barnard College in New York on May 14 was the perfect opportunity for that.

For no one can schmaltz and razzmatazz better than President Obama did in an academic gown at a graduation ceremony for successful liberal New York women. His speech was interrupted 36 times by applause and 22 times by gales of almost hysterical laughter — even for lame gags about how he was not going to do Michael Jackson's moonwalk. (From the official transcript: "‘No moonwalking.' [laughter]. ‘No moonwalking today.' [laughter].") Yet for all the banalities of his Barnard speech, a subtle reading between the lines, and a comparison of it with Mitt Romney's commencement address to Liberty University on May 12, tell us much about how this election will be fought.

Obama started off with his characteristic blaming of all America's economic ills on the previous Administration, telling the graduates how in 2008 "an economic crisis struck that would claim more than 5 million jobs before the end of your freshman year".  His own responsibility for prolonging the recovery was naturally sidestepped, and the blame placed on the undeniable facts that "Politics seems nastier. Congress more gridlocked than ever," as though he were a political commentator on ABC, CBS or NBC, or indeed anyone other than the man in charge.

His next scapegoat was the news media, because "good news doesn't get the same kind of ratings as bad news any more," although he didn't tell his audience when it ever did or, apart from North Korea, where it ever does. The dog-whistle was then blown long and hard when he told the assembled young women that "you're going to have to grapple with some unique challenges, like whether you'll be able to earn equal pay for equal work . . . whether you'll be able to fully control decisions about your own health." As sexual discrimination in pay has been illegal here since 1963, it hasn't been "a unique challenge" for nearly half a century. But the reference to women's health was intended to raise the bogey of the Republicans reversing the pro-abortion Roe v Wade decision — which is simply not going to happen in any foreseeable future — and also the genuine worry that Obamacare will be overturned by the Supreme Court as unconstitutional. Almost all the women in his deeply privileged audience will be able to afford health insurance once they graduate, assuming they get jobs in the Obama economy, and so would in fact have more control over their own health if the insurance industry does not fall into the hands of the state under the Obama proposals, but the whole point about dog-whistle politics is that it doesn't need to go into details.

He mentioned foreign oil, "the carbon pollution that's threatening our planet", "rules that stop big banks from making bad bets with other people's money", and lots about his daughters Malia and Sasha. "People ask me sometimes, who inspires you, Mr President? Those quiet heroes all across the country — some of your parents and grandparents who are sitting here . . . I'm only here because of them." It is corny lines like that which Obama hopes will see him through to a second term, and so schmaltzy has political discourse in this country become that he might well be right. The Oprah Winfrey-isation of life here extends far beyond the entertainment industry, and is such that it really may no longer be "the economy, stupid" that determines the outcome of this election. If being made to feel "empowered" and warm inside leads to winning votes — and every poll on the subject suggests that it does — then Republicans tolling the tocsin and warning about national bankruptcy, healthcare mayhem and loss of global hegemony may well be counter-productive.

It wasn't until his peroration that Obama got on to "how we achieved gay rights", claiming "That's how we made this Union more perfect." His recent backing for gay marriage is not without its dangers — not least among black evangelicals, whose reading of scripture can be as literal as any white Southern fundamentalist — but the polling has so far been roughly 54 to 46 per cent in his favour. The news, which broke on the same day as the President's announcement, that Romney had bullied an effeminate child at school 40 years earlier — to the extent that he was held down and had his hair cut off by Romney and his friends —could therefore not have come at a worse moment. The timing of the revelation was most probably orchestrated by David Axelrod's utterly ruthless White House campaign, for any Administration that would leak the details of the second al-Qaeda underwear bomb plot for good publicity is clearly capable of synchronising and contrasting the President's embrace of gay marriage with Romney's alleged aggression towards an individual gay boy.

One area where Romney has managed to minimise his negatives — at least so far — is over his Mormonism. Two days before the graduates of Barnard gave Obama 36 shrieking ovations, Romney was at Liberty University in Lynchburg, Virginia, which claims to "train champions for Christ". Founded by the late Reverend Jerry Falwell, the ultra-conservative university was until recently a local headquarters for the anyone-but-Romney campaigns that saw so many alternatives rise and fall as the Republicans chose their candidate. Even the choice of having a Mormon preaching there was criticised by some in the faculty.

The speech was a success. Romney showed modesty and good humour, and he got his points across well, with such regular references to Jesus that his audience was reminded that Mormons are Christians too. "Central to America's rise to global leadership is our Judaeo-Christian tradition," he said, while also slipping in great conservative statistics such as, "For those who graduate from high school, get a full-time job, and marry before they have their first child, the probability that they will be poor is 2 per cent." Of course he reiterated the standard Republican mantra that marriage is "a relationship between one man and one woman" (a curious choice of words, since so too is adultery).

Romney spoke of his turnaround of the 2002 Salt Lake City Winter Olympics — a central part of the Romney mythos — and the Christian faith of the recently deceased Chuck Colson, imprisoned for his part in the Watergate affair.  He stayed off the economy, since it was a commencement address, and calmed the anti-Mormonism of the Christian fundamentalists in his audience.

Yet he will need many more Liberty-style successes if he is to dispel the all-too widespread feeling that he might be a heartless Bain Capital exploiter, a "vulture" capitalist and even, in the words of Axelrod's latest vicious campaign advert, a vampire. The two-minute TV ad claims that when Bain Capital, whose founder and CEO was Mitt Romney, took over GST Steel in Kansas City in 2001, it pocketed the profits, ran up debts, declared bankruptcy and fired all the 750 workers. "It was like a vampire," says former employee Jack Cobb in the ad. "They came and sucked the life out of us." Never mind that Romney had left Bain in 1999 in order to run the Winter Olympics, or that the whole US steel industry was collapsing under the weight of cheap imports at that time, or that the Bain partner who actually took the decision to close the mill is today a top Obama fundraiser. The ad proves that the White House will stop at nothing to undermine Romney's reputation as a successful businessman, knowing that therein lies the President's greatest electoral Achilles' heel.

There will be many more such attack ads, most of them likely to be in very dubious taste as well as being tendentious. One released by the Obama campaign on May 2 — the anniversary of Osama bin Laden's death — suggested that Romney would have failed to order the strike, without giving any substantive reason for coming to that scurrilous and improbable conclusion. Americans are fully expecting a low-down-and-dirty fight this autumn, and for all his attempts to occupy the moral high ground in American public life, it is undoubtedly the President who is getting down lower and playing dirtier right now.