Do not be blinded by passion and excitement. Do not gamble on a dream that way. Rise to the challenge of being dull. “I am Hillary Clinton, and I endorsed this message.”

It may not be the most alluring pitch, but it has served well enough so far. Such a boastful lack of sex appeal in a political campaign does command a certain respect. And after two terms of President George W. Bush, Americans would give a lot for humdrum competence. The Democratic electorate is split in half and bracing for weeks and maybe months of further campaigning. Mrs Clinton, on some estimates, is still favourite to win the nomination.

Still, this was an audacious theme for her to adopt. Hillary Clinton, manager extraordinaire? It bears repeating that there is a single point of data to test this claim: her supervision of the healthcare task force set up by her husband during his first term. Opinions differ even now about that exercise – about whether Mrs Clinton was responsible for one of the most celebrated domestic-policy train wrecks in recent American history, a scapegoat for her husband’s misjudgments, or the hapless victim of organised special interests. What is undisputed is that the whole affair was an epic of hubris and mismanagement.

Yes, that was a regrettable episode, she now says – but she is the stronger for it, having learned from her mistakes. That is good to know, but since when was failure, unredeemed by subsequent success, a qualification for the top job? By all accounts, Mrs Clinton has been a fine senator, as has Mr Obama for a shorter time, but this is not an executive role. It is good political experience, to be sure, but (unlike having been the successful governor of a big state, for instance) it tells you little about fitness to manage, and less about fitness to be president.

The US is tired and discouraged these days. The country is right to seek a little inspiration, a lifting of the spirits, a sense of renewal. Mrs Clinton is the perfect antithesis of those things. She is commanding in debate; she knows her facts. But she is dreary and angry at the same time, which is no easy feat. She personifies partisan division. And, through her husband and her nostalgia for the 1990s, she is tied to the past. She is indeed the paradigm of business as usual, with the taint of dynastic succession thrown in. The Democrats would be wrong to make her their nominee, in my view, even in a field of unexceptional candidates – but this is not a field of unexceptional candidates.

Make no mistake, Mr Obama is a once-in-a-generation possibility. Admittedly, in many ways he is too good to be true. Hopes of what he might achieve are running out of control. His followers say he is uniquely able to restore US standing in the world, partly by adopting a more conciliatory approach and partly (it seems) by being black. The sad truth is that on many issues US interests diverge from those of other nations. Any new president could improve relations with other governments; the current administration has set that bar into the floor.

But if President Obama aimed first and foremost to advance US interests, as he would, then, regardless of how enlightened and encompassing his notion of US interests proved to be, overseas rapture at his election would quickly fade.

At home the disappointment might be worse. He is a liberal (the most liberal in the senate, according to National Journal’s annual assessment) yet running as a bipartisan moderate. If he were president, one of those tendencies would have to give way.

And then there is the question of race. Black Americans were initially sceptical about the Obama candidacy: they backed Mrs Clinton in early polls. But now they have come around, and how. They have decided he is real; they think he can win; and they long for this affirmation of their standing in the nation. Gratifying that longing is one of the best reasons to nominate Mr Obama, but be under no illusion that he or any other president could fix the problems that have created and entrenched the black urban underclass. Soaring expectations would have to come to terms with (at the very best) grinding incremental progress. Again, the disillusionment might be bitter.

All this is true, but secondary. What makes Mr Obama remarkable is that his message of hope, resonating so powerfully with black America, is cast to every American, regardless of colour, to Democrats and Republicans alike. This is surpassingly important: a man of outstanding intellect and magnetic personality, he is running on a one-nation platform, as though he merely happened to be black. And the best part is, the whole country is paying attention: polls say that he is more electable in November than Mrs Clinton. In a close election, he could make the difference.

Republicans, of course, are bound to dislike his liberalism – but what is there for Democrats to think about? Why are they even having this conversation? They have been waiting an awfully long time for a politician like Mr Obama. If, having come so close, they still manage to nominate Mrs Clinton, I think it is a choice they will regret for years and maybe decades.

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