The fall of Kevin Rudd's leadership was like one of those controlled implosions you see on the TV: an edifice one minute, a dust-cloud the next. It was initiated, as we know, by a small group of factional leaders. But the truly stunning part was the alacrity with which all but a few hardy figures in the Caucus piled on board.

Mr Rudd gave a fighting press conference at about 9:00pm, but within 12 hours he faced the truth; he had so little support that discretion (a gracious abandonment of the field) proved indeed the better part of valour.

What were the external circumstances at the time? Some average-to-discouraging polls, a couple of policy debacles, a grim stand-off with the mining industry. And the great leadership hiccup of the Rudd period, which was to effect an apparent reversal on climate change policy (a reversal to which he was urged by others, including Julia Gillard).

Fourteen months later, one would have to say the external circumstances have worsened. The Prime Minister still outpolls European carp and tinea, but only just. A further reversal on climate policy (this time 100 per cent the work and judgment of the Prime Minister herself) poisons the water. Her grand solution on asylum seekers has not only failed, but failed so spectacularly that the policy area itself has cannibalised the rest of her Government's work.

And yet, whatever the remarks unnamed Laborites might have made to the contrary in the tizzy that ensued after the High Court decision last week, there is no concerted move against the PM within the Caucus.

There's a fascinating, almost mathematical equation going on here.

With Julia Gillard, the probability that any given person will support the Prime Minister decreases with distance from the subject; she is supported by a majority of Cabinet and Caucus colleagues and viewed benignly in the public service, but despised by voters who have never met her.

Mr Rudd's equation is precisely the inverse; the warm support he continues to enjoy in the populace at large tails away sharply, the closer you get to the 2600 postcode. Outside Parliament House, voters might wonder why they can't bring that nice Kevin fellow back again. Inside it, people talk vigorously about chewing their own arms off before doing anything to hasten such a return.

Critics of contemporary political journalism often argue that too much is made of personality at the expense of policy. And that may well be right. But sometimes personality is the only explanation for an otherwise aberrant outcome. In this case, personality provides the principal reason that Julia Gillard bats on as Labor leader, while Kevin Rudd was handed his pink slip with unmannerly abruptness.

Certainly, Julia Gillard stays put in part because there is no immediately serviceable substitute. But her durability as leader is largely attributable to the mundane, day-to-day truth of the matter: She's nicer to her colleagues than Kevin was.

I don't think I'll ever forget the conversation I had with one backbencher a few months after Rudd's overthrow. "I agree with Kevin on just about every policy inclination he has," the backbencher said. "In fact, there probably isn't another person in the party with whom I am more in line." There was a pause, and then the backbencher added, calmly and without even the mildest hint of melodrama: "It's just that I hate him so very much."

Politicians are people. Their insecurities and petty stubbornnesses dictate their behaviour just like anyone else's do. There is no other way to explain this Caucus's tolerance of judgment errors committed by this leader, in counterpoint to its ruthless punishment of the last chap, other than the differences in personality.

How else can you explain the actions of the Rudd cabinet, so submissive to Mr Rudd's autocratic style that they were unable to challenge him on it in any constructive way, instead feebly adding their numbers, in the end, to a putsch engineered wholly outside their ranks?

Julia Gillard's personality is a matter for national conjecture. The People's Revolt has her pegged as a liar and a Leftist dictator. The ABC show At Home With Julia, which premiered this week, has her as an eager-to-please SuperMum type, soothing her neglected Tim with baby talk. Actress Amanda Bishop's impersonation of the PM is ferociously good, and her bum should win a Logie. But one could as much imagine the real Gillard showering her partner with treacly endearments as one could imagine her readily agreeing to process asylum seekers onshore. It's just not her.

The best parts of the real Gillard personality – her unflappability and wry, self-deprecating sense of humour – do not survive the camera more generally, for some reason. On television, she loses a dimension; her natural fluency seems to get snarled up in clunky catchphrases and rehearsed hand movements. Rather than looking like a leader forming a political argument, she tends to look like an AFL umpire reluctantly allowing a goal.

Mr Rudd, on the other hand, projects a public air of sunny, brainy nonchalance and a sense of sleeves-rolled-up efficiency which, colleagues say, belies a private pattern of coldness and inconsistency. The best parts of Mr Rudd's personality – his passionate desire to do good, and his genuine sense of fun – seem to wear down with familiarity. The Rudd of whom Caucus members speak so bitterly is every bit as alien to voters as the Gillard with whom Labor MPs are happy to work.

Kevin Rudd's colleagues cannot see in him what voters do: That's his tragedy.

And Julia Gillard cannot make the nation see why her party hangs on to her: That's hers.

Annabel Crabb is the ABC's chief online political writer.