One of the most fascinating sights I've witnessed thus far during the coverage of the 2010 election campaign is Gordon Brown's visit to a branch of Tesco in Hastings on 16 April, which was broadcast live and uninterrupted for about five minutes on Sky News.

"Hello, good to see you," says Gordon, shaking someone's hand. "It's great to be here," he continues, waving at a well-wisher. He looks around. "This is a good store, isn't it?" he enquires of no one in particular. He spots a young boy. "How old are you?" he asks. The boy is eight. "That's a good age," Gordon concludes. "Which football team do you support?"

As he continues walking through the supermarket, the pictures carry on moving, but the sound appears to be stuck on a loop, because Gordon's repeating the same words. "Hello, good to see you." "It's great to be here." "This is a good store, isn't it?" "How old are you?" "That's a good age." "Which football team do you support?" The same handful of phrases, over and over again, for five minutes.

When you watch the footage repeatedly, as I have, distinct patterns start to emerge. Throughout the visit, Brown looks marginally less comfortable than a horse crossing a rope bridge, and his internal dialogue tree is starkly visible. Whenever he meets a boy of eight years old or older, for instance, Gordon briefly asks which football team they support, then chuckles, whatever the answer, before moving on to say "Hello, good to see you" to someone else. That's the way he's been programmed. (He occasionally breaks up his repetitive mantra with brief statements of the obvious: at one point, he glances at a shelf full of produce and says, "There's a lot of produce here." It almost makes you wish he was being shown around an orgy instead. Almost.)

The footage is funny, yet somehow heartbreaking. Brown looks clumsy, ungainly and chronically unsure how to behave around everyday shoppers. He reminds me of me. I can scarcely look people in the eye in supermarkets either. But I've learned to survive in demanding public situations – such as standing in front of an audience of expectant strangers – by adopting a babbling, deliberately awkward, vaguely nihilistic persona that is 50% me and 50% comic construct.

It's a shield of radioactive bullshit that hopefully provides just enough entertainment value to stop the crowd physically attacking me, and just enough psychological distance to stop me crumpling to the floor and ripping my own face off at the sheer uncomfortable weirdness of it all.

Thing is, this performance wouldn't withstand five minutes of serious scrutiny. I could open a supermarket, no problem, but sit me opposite a combative Jeremy Paxman and I'd have a massive nervous breakdown within five minutes. With Brown, it's the other way around. In the supermarket, he looked so anxious I half-expected him to climb inside a freezer compartment and refuse to come out until everyone else had left. In his interview with Paxman, held in the wake of the preposterous Bigotgate storm and a widely criticised final debate, he was frighteningly confident. At times, he even seemed to be enjoying himself. Technical in the social situation, sociable in the technical situation? That's the hallmark of a nerd. And most nerds are simply too gawky – gawky, not aloof – to connect with the general public.

So he's not endearing. The press held up Brown's Bigotgate outburst as evidence that he's two-faced and contemptuous of everyday people, especially those who mention immigration, a subject so taboo in modern Britain that even fearless defenders of free speech such as the Mail and the Express only dare mention it in hushed capitals tucked away on the front page of every edition.

Two-faced contempt is the basic mode of operation for many newspapers: mindwarping shitsheets filled with selective reporting and audacious bias. The popular press is a shrill, idiotic, bullying echo chamber; a hopelessly poisoned Petri dish in which our politicians seem resigned to grow. Little wonder they develop glaringly artificial public guises. Picking a modern leader boils down to a question of which false persona you prefer. At least Brown's is almost admirably crap. It's easy to see through it and catch hints of something awkwardly, weakly human beneath.

Clegg's persona is roughly 50% daytime soap, 40% human, and 10% statesman. Cameron is 100% something. He isn't even a man; more a texture-mapped character model. There's a different kind of software at work here, some advanced alien technology projecting a passable simulation of affability; a straight-to-DVD retread of the Blair ascendancy re-enacted by androids. Like an ostensibly realistic human character in a state-of-the-art CGI cartoon, he's almost convincing – assuming you can ignore the shrieking, cavernous lack of anything approaching a soul. Which you can't.

I see the sheen, the electronic calm, those tiny, expressionless eyes . . . I glimpse the outlines of the cloaking device and I instinctively recoil, like a baby tasting mould. Don't get me wrong. I don't see a power-crazed despot either. I almost wish I did. Instead, I see an avatar. A simulated man with a simulated face. A humanoid. A replicant. An Auton. A construct. A Carlton PR man who's arrived to run the country, and currently stands before us, blinking patiently, blank yet alert, quietly awaiting commencement of phase two. At which point, presumably, his real face may finally become visible.

• More Guardian election comment from Cif at the polls

This week: Charlie wanted to draw your attention to the release of Chris Morris's film Four Lions on Friday, which should cheer you up whatever the outcome of the election, unless you hate laughter or fun.