As David Shearer looks to hit the road, some are asking whether he was Labour's golden opportunity missed. So is that nostalgia or wise hindsight speaking?

I remember talking at a do with a Labour apparatchik in December 2011. The party had a new leader and there was a sense of excitement. "We can get him on the cover of NZ Surfer. When's the last time Labour could say something like that?", this person enthused.

David Shearer had fulfilled his early potential, if perhaps a little more rapidly than was good for him. He was leader of the Opposition, the heir to Helen Clark in Mt Albert and, as many Labour folk called him, "our John Key".

Like Key, he had come home after a stellar career offshore to make a difference, do his bit and make his mark. The comparison was irresistible; except where Key had made money, Shearer had brought peace. And he played guitar. And owned a caravan. A spin doctor's dream. A kiwi bloke, with brains and a heart.

But that Key comparison quickly began to haunt him. He was not as ... composed. While Key had four years in parliament before being asked to lead, Shearer had only half as long. But opportunity comes knocking when it does, not when you'd like it. And Shearer had to adapt quickly. He struggled with the media and to articulate a clear idea of where he stood. Heck, he struggled to finish a sentence.

But perhaps his biggest problem was that he had opponents within the party and, unlike Key, was unable to subdue them. And really, you can't overstate the importance of having a unified party behind you.

Key shook off some of his party's unelectable bits without shaking off supporters. Shearer couldn't do the same. He was regarded as too centrist by many; those who wanted to win on their own terms and pull Labour to the left. 

David Cunliffe kept throwing curve balls from his left, and he never really got stable footing. Yet for all that he took Labour to its highest poll numbers since Helen Clark. Under Shearer, Labour got to the magic 'mid-30s' that they so desperately need to reach if they want to be in government again. They were hinting at being able to choose between the Greens and New Zealand First.

At least a few in and around Labour watched Key resign this week and thought, 'bugger. If only we had Shearer now'. It's a tempting view. But is it realistic?

I've gone back and forth on this in the past couple of years. On one hand, Shearer ticked all the boxes as a winner from the centre and is clearly a talented and likeable man. He was canny too. I remember when he was running against Cunliffe for the leadership in 2011 he rang Paul Holmes to secure his backing. Holmes' Herald column was influential and Shearer was quick to woo such backers. Cunliffe missed that trick, but spoke to Holmes later, apologising for not showing him proper respect by pitching his own woo.

Cunliffe didn't take no for an answer though, and undermined Shearer at every turn. You could call Cunliffe divisive, but he only had the chance to destabilise because Shearer never quite looked stable. The fact remains Shearer was unable to suppress his critics by his own performance. Key shut up his detractors on the right pretty quick; Shearer couldn't control the left.

Further, Shearer wasn't just a poor communicator, he was poor with detail. He had good political instincts, but often seemed to have never quite done his homework.

At the 2014 election, Shearer as Labour's Energy spokesman, went rogue releasing his party's mining policy on The Nation. Team Cunliffe had been stalling him in his attempts to get his policy out in election year. Finally, in frustration, he decided to come on the programme and announce, without telling the leader's office.

When they found out late on Friday, they were furious and tried to pull him off. But he wasn't for turning.

The policy reflected his centrism; backing drilling for oil and jobs over environmentalism. But the policy was also only skin deep. It may have been that he didn't have the support or resources he needed, but whatever the reason he lacked answers to the detailed questions. He was flying by the seat of his pants.

There has always been a sense with Shearer that he is best on the fly, good in a crisis. Maybe not one to do the hard yards. On the other hand, Kiwibuild came out on his watch. Even while he was cursed with too much contradictory advice and struggled to speak in full sentences, voters saw something in him. Maybe his timing was just unlucky. Maybe he never really got the time and clear air he needed to grow into the detail.

Or is that nostalgia?

Either way, you can't help but wonder what might have been had Shearer come to the job after Cunliffe, rather than before. If the party had got Cunliffe out of its system before rallying behind Shearer, perhaps his political appeal would have been buttressed by better support from within the party and a few more years of experience.

But we'll never know. Instead, Shearer will have more time for surfing this summer.