It is now widely accepted that nothing has damaged the Labour party in Scotland more than their role in the independence referendum campaign.
A new poll of Labour-held Scottish seats suggests that support for independence is now the overwhelming reason why former supporters now back the SNP.
According to Comres, 56% of SNP voters in Labour-held seats say their desire for independence is one of two main reasons they are now backing the nationalists, with 35% saying that "Labour no longer represents people like me" and 30% saying "the other parties have broken promises on devolution."
Tellingly, almost a third (29%) say "the way Labour campaigned with the Conservatives during the referendum" has caused them to vote for the SNP. By contrast just four per cent say they are voting based on the quality of their local candidate.
However, while the independence campaign has clearly caused a collapse in Labour's support north of the border, the rot actually took much longer to set in.
Long before the referendum was announced, the perception that Labour had taken Scottish voters for granted had grown, as the party increasingly concentrated its resources and attention on winning over an ever-narrowing selection of mostly English marginal seats.
It is this attitude - that Scotland would be forever Labour so didn't need to be bothered with - which in the end proved most damaging for the party. It is an attitude they appear reluctant to let go of.
Deeply uninspired by Jim Murphy's sense of entitlement to power as outlined on Today programme. All about Tories & SNP.— Caron Lindsay (@caronmlindsay) April 1, 2015
Speaking on the Today programme this morning, Jim Murphy repeated his line that the most pressing issue facing Scotland is whether they will have a Labour or a Tory government. By daring to stand and win against Labour, the SNP were merely being "David Cameron's little helpers" he said, adding that "David Cameron can't win seats in Scotland… so he has to get someone to beat Labour for him".
This idea that anyone who stands against Labour must therefore be pro-Tory uses such obviously false logic that it is almost embarrassing to hear it and yet it is an argument you hear Labour using time and time again.
More importantly this argument betrays a level of arrogance. It betrays a belief that somehow Scottish voters 'belong' to Labour and anyone who dares to think otherwise must therefore be a secret Tory shill.
This mindset was encapsulated today, as Murphy tried to explain why Scottish people should still vote Labour.
"The SNP are just getting in our way of forming a government," he said.
Let's just think about that sentence for second. Can you feel the entitlement? Can you feel the assumption that Scotland somehow belongs to the Labour party and the SNP should just play nice and hand it back?
It is this belief which has driven Labour's collapse in Scotland. It is this attitude, above all, which explains why Labour have won back such little ground since Murphy took over last year.