Some of the first conversations on Twitter last week after Key's electric performance on Campbell Live were how inadequate Shearer would look against him in election debates.
Even when Shearer performed creditably as he did at the Auckland Town Hall meeting on the GCSB bill, he is almost always out-performed by Greens co-leader Russel Norman.
Even the good times were bad. This week's stunt of bringing a couple of dead snapper into the House didn't impress many of the caucus but it wasn't the clincher.
It has been a leadership not so much in decline, as never taking off.
Shearer was a risk his supporters thought worth taking in 2011.
He was installed as leader by a combination of the right faction, and the part of the left faction that did not want David Cunliffe and who supported Grant Robertson as a future leader.
They knew that Robertson wasn't ready but in David Shearer they saw someone who could emulate the John Key success story - someone who was new to politics, who was seen more as a decent person, an outstanding humanitarian than a hardened politician.
Shearer was no match for Key who had been in politics for nine years and Prime Minister for three of them by that time.
Shortly after Shearer was elected leader in 2011, he asked John Key if he had any advice as the pair walked from the debating chamber to the Legislative Chamber for the opening of Parliament.
Key advised him to seize the moment and to make the most of his leadership in the early stages to push through the ideas he wanted early on.
Shearer didn't seize the moment, then or at any time.
One colleague said he didn't come to the top job with enough well-formed views, experience of how Parliament worked or the Labour Party worked.
He may have made an excellent Prime Minister but with his apprenticeship as an inexperienced politician in the most demanding of parties against a talented Prime Minister, the chances of getting there have been diminishing.
As one senior party member said yesterday: "He couldn't inspire, he couldn't communicate, he couldn't think on his feet. He's an honest person so he couldn't bullshit like Key."
Shearer's deficiencies were forgiven in the first year of his leadership but not the second.
He has had a distant and difficult relationship with the party which has lost the discipline it had under the Clark years.
The original open contest between Shearer and Cunliffe empowered the party and heightened the differences between the caucus and the party - the party tolerated his leadership at best.
The beginning of the end started in June when Labour slumped back to 30 per cent in the polls after having climbed to a respectable 35 per cent in the first half of the year.
The slump started rumours about spring coups.
The whispering was followed by the women-only selection proposal, dubbed the man-ban issue. For once Shearer was decisive and it played well with the public, but not with the party.
For him it was a no-win situation, the story of his leadership.
