The speed of the new consensus is perhaps the most remarkable thing about it. All it took was a new movie on global warming, fresh doubts about Hillary, and a growing desire to expunge George W Bush from the national memory banks . . . and suddenly Al Gore is anointed by the chattering classes as the next Democratic nominee.

Al Gore? Yep. The man who, after eight years of peace and prosperity as vice-president, couldn’t manage to persuade Americans to continue the Clinton legacy with a president who could keep his trousers on. The man who sighed and huffed his way into debate oblivion in 2000. The man who grew a beard and slunk off to Tennessee in disgrace after the cliffhanger. Al Gore, national joke . . . now national saviour?

It is indeed a little hard to believe. But bear with me. Stranger things have happened in American politics.

The most obvious historical parallel is Richard Nixon. He too was vice-president for eight years of peace and prosperity under Eisenhower, and he too lost an extremely close election for president in 1960 (and probably should have won, if the dead hadn’t managed to vote in Illinois).

He came to lose another bid for governor of California and subsequently quit politics altogether, telling the press they wouldn’t “have Nixon to kick around any more”. But eight years after his presidential defeat, Nixon was in the Oval Office. A war gone awry under a president who was on the ticket that beat him, Lyndon Johnson, paved the way for a Nixon victory. Sound uncannily familiar?

And just as there was always a “new Nixon”, so now there is now a “new Gore”. He is relaxed and forceful, his acolytes keep saying. He has found his voice. He has freed himself from the focus groups and the pollsters and the caution that crippled his candidacy in 2000. Arianna Huffington gushed after a screening of the newly released Gore movie on global warming: “As I watched him interact with well-wishers, accepting congratulations and answering questions, he radiated commitment and confidence. Here was a man truly comfortable in his own skin.”

Please. Al Gore is Al Gore. One reason he seems much more comfortable today is that he is no longer running for office, a vocation forced on him by two overweening parents. Gore loves policy and loathes politics. Of course he’s happy and confident now. Both his parents have died and he can relax on his porch in Tennessee and think about fluorocarbons.

He’s doing what he loves — hanging out with the coolest geeks on the planet (he’s buddies with the Google guys), appearing on magazine covers (Vanity Fair, Wired and New York magazine this spring alone), and now premiering an infomercial, An Inconvenient Truth, that’s finally giving emission reductions the attention they deserve.

But, despite his tenacious, unelectable Goreness, the logic behind him as a future political entity is still solid. I know of very few Democrats enthusiastic about Hillary. The left-liberal base is enraged by her calculated centrism; the Republican party at this point could unite only if she ran against it; and questions about the Clinton marriage appeared on the front page of The New York Times last week as a virtual editorial begging her not to run.

Gore, moreover, has been proved right about a subject he’s been boring on about for decades. The past few years have revealed an accumulation of new data that have persuaded even sceptics like me that global warming is real, man-made and potentially hazardous. In politics, timing is everything, and, finally, Gore has it.

On national security, Gore also manages to assuage the American centre. He has a long track record of hawkishness, especially with respect to the Middle East. He knows defence policy well, and was a strong supporter of the use of military force within the conservative wing of the Democratic party for years.

Americans would not, I think, fear a Gore presidency on matters of defence. Most other Democrats are much more vulnerable on this score, which matters after 9/11 much more than it did in the Clinton fin de siècle. What Gore would add, moreover, is a genuine, impassioned and justified revulsion at some of the tactics that the cabal of Dick Cheney and Donald Rumsfeld has deployed: torture, rendition, warrantless wire-tapping and unnecessary estrangement from allies.

John McCain, the Republican senator, could pull off that combination of hawkishness and honour as well. But few other Democrats could do it with the same assurance as Gore.

Then there’s the issue of karma. Gore won the popular vote in 2000. If a few old Jewish ladies in Palm Beach had not been confused by their ballots and voted for Patrick Buchanan, Gore would have won Florida as well — and the presidency. Everyone knows this — and that election still wounds America in ways that a Gore candidacy might assuage.

Gore’s penchant for detail, for policy wonkery, has also, in the wake of Bush, come to seem less of an irritant and more of an asset. After watching the incompetence in Iraq and after Katrina, Americans are beginning to want a president who is interested in how government works. Bush never has been. That was his charm. It has also proved his undoing.

So Gore v McCain? Or Gore v former Virginia governor George Allen or Massachusetts governor Mitt Romney? It’s possible. A Gore-Hillary fight in the primaries would also be a crack for hacks. There’s a reason the press is now all but drooling over the potential.

And the Democrats are hungry enough for victory that they might give him a second chance. I can still remember the sad bumper stickers from two years ago: “Re-elect Gore in 04”. But I also recall the ineptitude of the 2000 campaign, the tone-deaf rhetoric, the palpable unease in elective office that made Gore — and the rest of us — miserable for so long.

If he really is a new man, if he really is finally comfortable in his own skin, he’ll stay on his porch in Tennessee. Or be dragged by his party, huffing and sighing, off it.

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