The advantage of reasonableness is not arriving at new, better judgments. “Reasons” are usually more sophisticated explanations for what you would have believed anyway. Between the first and second presidential debates, I tried to convince myself that Barack Obama’s disastrous initial performance didn’t matter – or, even better, hinted at deeper qualities. I must have known, at least subliminally, that I was justifying a position rather than developing one. But I couldn’t help doing it anyway.

Yes, Obama looked tired and uninspired – but he was busy running the country. Yes, he failed to provide a compelling case for re-election – but intellectuals find it hard to articulate a simplistic narrative. Yes, Obama looked flummoxed by Mitt Romney’s abandonment of the right and his new incarnation as “Moderate Mitt” – but perhaps Obama was genuinely amazed, having paid his opponent the respect of taking Romney Mk 1 at his word?

Real deal

By the time Obama did show up in the second debate, I had carefully polished my theories on why the first one hadn’t mattered. First, consider the sharp difference between a televised advertisement and running the country. Romney, a practised salesman, enjoyed selling his favourite product: himself. Obama looked distracted, embarrassed and bored. That may not be a good electoral strategy but it’s an attractive strand of psychological authenticity.

Repeating “I’ve got a five-point plan” is easy. Being president demands dealing with a flow of decisions to which there is no “right” answer. “Nothing that comes to my desk is perfectly solvable,” Obama told Michael Lewis in his Vanity Fair profile. “Otherwise someone else would have solved it. So you wind up dealing with probabilities. Any given decision you make you’ll wind up with a 30 to 40 per cent chance it isn’t going to work.” In the real world of leadership, this kind of probabilistic thinking is essential. On television, the fashion is to look 100 per cent sure of everything. When you’ve given the order to kill Osama bin Laden and tried to negotiate a massive economic crisis – and made all your decisions under conditions of uncertainty – a charade of Punch-and-Judy politics probably does feel demeaning and boring.

Second, I was beginning to like this aloof, withdrawn Obama more than the soaring rhetorician of the 2008 campaign. The less he seemed to care about being liked, the more I liked him. After all, why should we expect our politicians to exhaust themselves pretending to feel emotions that would inevitably – if they felt them – make the job of governing almost impossible? If politicians “cared” as much about everything as they are told they must, then government – the business of choosing between difficult options – would grind to a halt.

How reassuring that a president had emerged who was not addicted to emoting. Justin Webb, the former BBC chief Washington correspondent, recalls talking to Obama about stem cell research into type 1 diabetes (a disease that had stricken Webb’s son): “He knew more about this unusual autoimmune condition than I did. He knew the science . . . But he did not feel my pain, or pretend to. He remained separate . . . Where Clinton would have grasped my hand and Bush would have had us on our knees in prayer, Obama kept his cool.” I am much happier knowing that the president’s instinct is to discuss issues seriously rather than press flesh.

Finally, I reassured myself that Obama had not lost the first debate after all. He’d clearly lost. But it wasn’t a debate. Modern political debates aren’t worthy of the title. They are a series of choreographed soundbites interrupted by other choreographed soundbites. As George Orwell argued in his 1946 essay Politics and the English Language: “The concrete melts into the abstract and no one seems able to think of turns of speech that are not hackneyed: prose consists less of words chosen for the sake of their meaning, and more of phrases tacked together like sections of a  refabricated hen-house.”

This lament should not be confused with the wonkish complaint about a lack of “policy detail” (wrongly assumed to the panacea for empty soundbites). The real problem with political debates is that there is no progression in the argument. For a debate to be interesting, there must be genuine engagement – the possibility, at least, that unexpected common ground may emerge from the exchange of ideas. Because political strategists focus on avoiding gaffes, their candidates eschew all risks – such as the potentially devastating strategy of agreeing with your opponent when he least expects it (to change the minds of others, it helps to demonstrate that your own mind can changed). A real debate has an intellectual progression, something far deeper than the projection of confident assertion. Had it been a real debate, I consoled myself, Obama surely would have won it.

Cause and effect

I stand by all these arguments for not downgrading my assessment of Obama. But during those 13 days between Denver and Long Island, I had a more unsettling realisation. None of these “reasons” for my support of Obama were reasons at all. They were rationalisations of support that would have continued anyway. Let’s address the question of causality as a historian would: had my observations about Obama truly been reasons, then the absence of those characteristics would have led me to stop supporting Obama. If Obama had been punchy, energetic and abundantly clear, my support would have declined – which is obviously not the case.

I still think I’m right about Obama. But if I’m honest, I can’t tell you where that conviction comes from. “So convenient a thing it is to be a reasonable creature,” wrote Benjamin Franklin, one of the Founding Fathers, “since it enables one to find or make a reason for everything one has a mind to do.” And here’s the thing. I’m in the vast majority. Only a tiny minority of viewers are open to changing their minds.

On that single point, I’m pretty sure I’m just stating the facts rather than trying to find reasons why the first debate didn’t matter.

Ed Smith’s “Luck: What It Means and Why It Matters” is published by Bloomsbury (£16.99)