The battle for the Labour leadership was first waged in caucus (Shearer), then on TV (Cunliffe). This week it moves to the regions as remains tight. So who does John Key fear most? And why do I keep thinking of Obama & Clinton?

The Labour leadership race is closer than is being spun, in part because Phil Goff's people still have their hands on the spin levers and Goff is backing David Shearer. As in any election, this race will come down to the undecideds.

My reading is that Shearer still has the edge and momentum, especially outside the party; and the lust within Labour for something fresh and untainted won't ebb in a matter of days. But untainted also means untested and momentum can be fickle. David Cunliffe has had his opponent's measure in the weekend politics programmes and both the viewing public and Labour MPs would have taken note of his sharpness.

As one perceptive viewer emailed to Q+A this morning - one of the men is like John Key and one is not. Labour must decide whether it wants its own likeable leader to out-Key Key, or whether a wind-shift is coming and choose to change tack. 

On both TV One's Q+A and TV3's The Nation, Shearer was caught short. Cunliffe, as I've written before, has become a very good television performer, so the battle was certainly fought on his turf and terms this weekend. For Shearer it's a new environment and, quite apart from the quality of his answers, it showed in his body language and demeanour. He didn't look confident; he took half a second before each answer, when you could see him thinking about what the wrong answer might be and whether he was about to get himself into trouble.

This morning on Q+A came the 'Brendon Burns moment'. Guyon Espiner asked who Labour's Climate Change spokesman was during the campaign; it's a trick Guyon has played on many of us, and almost everyone (me included) has answered Charles Chauvel.

The answer, of course, is Burns. Shearer didn't know, Cunliffe did. In and of itself it's just a very minor gotcha. People at home won't have cared, but it will have given those Labour MPs pause. Just how well does Shearer know his own team? Has he the necessary grasp of detail? And the lingering camera shot on Shearer showed him looking at the ceiling and ruing his answer.

Cunliffe was also smart to tie Shearer to the Goff camp. It paints the Mt Albert MP as less the 'fresh face' and more a continuation of the past three years, which ended in failure.

Shearer wasn't born yesterday though. He talked about Labour being "locked in the past" under Goff; presumably his backers realise he needs to lob a few grenades at them to stress his independence. When Cunliffe gave a cautious answer on the SAS going into Afghanistan, Shearer showed more gumption, taking over the answer with conviction, saying 'I'm the aid hero, foreign policy is where I'm strong'.

Shearer also made sure he got a wee story in about "trying to get a little guy through the Israeli checkpoint to get to a Palestinian hospital ", as an example about his passion for the under-dog.

I've no doubt he's being advised to remind people of his aid heroics at every turn. Even Cunliffe is reported as having described him to voters as "a cross between Mother Theresa and Indiana Jones". That's a potent image and is probably why John Key, for now at least, is more scared of Shearer than Cunliffe.

But Shearer's going to have to sell his story with more conviction. He ended that story... "or something like that". His delivery has some way to go. But the extra confidence should come.

The challenge perhaps is that Shearer would need to change the political culture to his strengths, and that's a massive ask. As John Tamihere cannily observed, his leadership style is more about unifying and negotiating, which is not the default setting of the political world. Cunliffe would bang more heads together, is more 'of that world'. Although wary of that image, Cunliffe went out of his way today to say he knows he's annoyed people in the past and would work to mend bridges.

What those voting Labour MPs need to consider are both men's weaknesses, because they will be writ large eventually, whoever wins. Cunliffe seems to spark strong negative first impressions. People use the word "slick". Because he's got such a carefully tailored political career, there seem to be questions around authenticity.

Now some on the left say he's been a hit with union delegates and is liked and admired by the Greens; that last being a crucial factor in the next three years for any Labour leader. But the doubt remains whether voters will take to him, or be put off by his confidence and, at worst, his air of intellectual superiority. Cunliffe's curse is that he is smarter than most people. But New Zealanders hate being talked down to more than just about anything, so can he get around that?

Shearer's weakness is the flipside of his strength - he's so very, very new. He has momentum because voters and journalists have embraced him like a new toy. He's a shiny new plaything, which is very useful in this post-political age when people want to like who they vote for, not just admire them.

But newness is finite. What happens when the gloss wears off? Are you left with a man of substance and someone who can compete with National?

I just don't know. But I'm reminded of the most recent Democratic primary - Clinton v Obama. Obama was the fresh face, the reform candidate. He exceeded expectations and over years of campaigning came to embody change, his catch-cry. I had many arguments with American friends that freshness may be great on the campaign trail, but how does it translate in the White House? Surely Clinton has the substance and bloody-mindedness needed to govern and effect change in the political swamp. I doubted Obama and I think I've been proved right.

I know that sounds like a count against Shearer, but it's not meant that way. There are many flaws with that comparison. The past presidential election was the Democrats to lose; here 2014 will be 50-50. And maybe Shearer is tougher than Obama, maybe Cunliffe simply won't be able to connect with voters, which makes the question of governance academic.

My broad point is simply that change is not enough on its own; it doesn't last. Winning over voters is only one part of the trifecta. You have to go past that and ask 'what kind of change would he bring?' and finally, if voters can be convinced, 'who would make the best Prime Minister'? 

The test now turns to the closed-door regional party meetings throughout the country this week. Which man can put some meat on the change skeleton, convince member he can re-connect with voters and show he can beat John Key (and whoever may come after him)?