How do you solve a problem like Obama? I refer to the immense difficulty of running against him. Senator Hillary Clinton has found that out the hard way. She clearly assumed as recently as Christmas that it would be relatively easy.

And you can see why. She had all the party machinery, all the chits accumulated over two decades, the biggest brand name in Democratic politics, a former president actively campaigning for her, a majority of the black vote, the women’s vote, the Hispanic vote – and a set of policy positions that were almost identical to the black freshman senator with a funny name that sounds like Bin Laden.

Only last December she predicted it would all be over by February 5. And yet on every score she has been bested so thoroughly she barely knows even now what hit her. You should never count out the Clintons. It’s not over yet. But one thing we have all learnt this past year is that no one should underestimate the raw political talent of Barack Obama. Combine that talent with this moment in American history and it’s a very powerful force.

How should the Republican front-runner John McCain respond? Unlike Clinton he has had plenty of warning. And last week he tried out a few test runs. He insisted that he alone has the experience and training to be “ready on Day One” for the presidency in a time of war. He has mocked highfalu-tin rhetoric as no substitute for a long, detailed record on national security. And then, last Thursday, he went further. He tried to neutralise Obama’s biggest advantage: that he had been against the Iraq war while McCain had been for it.

“That’s history, that’s the past,” McCain told a crowd at Rice University in Texas. “That’s talking about what happened before. What we should be talking about is what we’re going to do now. And what we’re going to do now is continue this strategy which is succeeding in Iraq and we are carrying out the goals of the surge, the Iraqi military are taking over more responsibilities.”

It makes sense. The latest poll finds a small up-tick in optimism about progress in Iraq, with 48% of Americans now believing the military effort in Iraq is going well or fairly well, compared with 30% who felt the same way a year ago. But even as that number has risen, the proportion believing that the war was a mistake has stayed fixed at 54%. Americans are flexible but not stupid. Hence McCain’s attempt to change the subject.

He may well not succeed, and if the fragile Iraqi lull does not hold – and national political reconciliation seems as remote there as ever – he could come a cropper. Worse, McCain is stuck with a downside of possible Iraq success as well. Why? Because the more the surge is perceived as succeeding, the easier it will be for Obama to argue that the US can now withdraw. We won, right? Time to leave. Paradoxically, a success for the surge could remove McCain’s strongest card on national security by making withdrawal far less dangerous. President George W Bush and McCain have managed somehow to box themselves in: if the surge fails they lose, if it succeeds the public is more comfortable handing the reins to a young Democrat.

And attacking Obama directly carries risks. All the usual slime has been thrown already. The Clinton camp has tried it all, and has come up empty. And that’s with a large wedge of Democrats on the Clintons’ side.

If McCain tries gambits such as going for the Arabic-sounding name, or a tenuous association with the black firebrand Louis Farrakhan or conflation with Jesse Jackson, he runs a real risk of sounding racist in ways that will turn off critical white swing voters, and galvanise Democrats, especially the burgeoning younger vote, behind their man. And the bulk of the hardcore racists are all locked into solidly Republican states anyway.

For what it’s worth here is my advice for McCain. Don’t run on experience. It hasn’t worked with Clinton and it won’t work for him. In McCain’s case it speaks for itself. Why downplay this obvious asset? Because this is a “change” election. If the economy continues to tank, it’s going to be even more of a change election. Remember the Bill Clinton mantra in 1992? “Change versus more of the same.” It worked. And it will work even more this time, since the number of Americans believing that the country is on the wrong track is even higher than in 1992.

Moreover, the whole “experience” and “readiness” theme would reinforce McCain’s biggest liability in the obvious narrative of the 2008 election: the old versus the young. He will seem like an establishment figure whose time has gone.

What McCain has to do is to coopt Obama’s message. McCain has to become the change candidate. He has a record that makes this plausible enough. He has long been a rebel in Washington: he has tackled Republican rigidity on climate change, spending excess and the war. If anyone can be said to have forced a change in strategy in Iraq, it is McCain.

What he needs to do is to reiterate that he brought change once before to Iraq and can bring it again, by orches-trating a withdrawal that is as careful (to paraphrase Obama) as the invasion was careless. But he needs to broaden that message, adding diplomacy to his theme. He should embark on a world tour of allies in the spring, reassuring Americans and the world that he will reverse America’s not-so-glorious isolation. As a former prisoner of war he can credibly insist that he will change America’s interrogation and detention policies, and restore its moral standing. He should revisit David Cameron and other leaders to talk about climate change.

Obama’s weakness is on his left-wing economics. But McCain should not attack there either. He should propose a broadside on pork-barrel spending, a commitment to fiscal retrenchment, a reform of entitle-ments and a pledge to ratchet back the massive expansion of government under the Bush Republicans.

At some point McCain should also risk a fight with some of the uglier elements of the far right. The country is sick of figures such as Ann Coulter, the conservative columnist. A Republican version of the famous “Sister Soul-jah moment” in 1992, when Bill Clinton publicly took on an African-Ameri-can rapper for violent antipolice rhetoric, would signal a willingness to shake things up.

McCain has two tendencies: to react with prickly intransigence to criticism and to inspire others with the record of his own public service. Many of his fellow Republicans will urge him to savage Obama on his youth, inexperience and liberalism. If that is the strategy, McCain will implode. But if he can master his own volatile temperament and out-Obama Obama on change, he stands a real chance.

But it won’t be easy. Just ask Hillary.

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