The Democratic Party has made its biggest mistake since… well, the last presidential election. Worse than that, really. Barack Obama is a disaster of McGovernesque proportions, and his nomination will give the McCain camp confidence that what should have been an unwinnable election will be within reach.

Let’s be clear. Obama is the weakest, least substantial candidate from either side for a generation or more. At least Michael Dukakis had run Massachusetts. Obama hasn’t run anything, has been in the Senate for five minutes, and has an undistinguished record in Illinois.

All he’s got are words – eloquent, uplifting, energising and wholly vacuous words. And nothing else. Particularly, no experience.

The likes of Hu Jintao, Mahmoud Ahmadinejad and Vladimir Putin must be rubbing their hands with glee at the notion of dealing with a United States presided over by such a foreign policy toddler like Obama. The absurd comparisons with Kennedy (usually JFK, but if it’s a floundering Hillary Clinton, maybe RFK as well) miss the critical point that Kennedy viewed the presidency through the prism of foreign policy, in which he had substantial expertise. Kennedy knew enough about foreign policy that he was his own Secretary of State, with Dean Rusk running State. The notion of Obama doing the same is frightening.

That’s assuming he ever gets there. The Republican political machine is the most vicious on the planet (amongst those that don’t kill people, that is). Courtesy of the Democratic primaries, it has a wealth of material on Obama. Clinton’s attack ads, while providing a useful playbook, will look innocuous once the Republicans fire up. And there’ll be no rising above this sh-t fight with plaintive pleas for “a new kind of politics” for Obama. The old politics still works very well.

Worse, in John McCain he’s up against about the only Republican with sufficient product differentiation from the Bush Administration to be competitive. There was a telling comment about McCain back in 2000 when he was battling Bush: “he’s what presidents used to be like”. The war hero thing, the maverick reputation, even his age, tap into the sort of president that exists only in movies, but which McCain may be able to channel.

Obama’s only hope is to get Clinton onto the ticket. A solid core of Clinton supporters have consistently said they won’t vote for Obama. A lot of that will be resentment at Clinton’s (grotesquely unfair) treatment at the hands of the press compared to the golden ride Obama has had, and will vanish once the battle is joined. But Obama already has too many major constituencies who have consistently demonstrated they won’t vote for him – lower income workers, Hispanics – to afford to alienate core Democrats who not merely vote but help organise and get out the vote and, crucially, donate.

It might stick in the craw, his supporters might loathe the idea, but bringing Clinton on board will be the smartest thing Obama will do all year.