Here's a good, unscientific bet:

if Scottish Labour had been inundated with membership applications after the referendum, we would have heard all about it. If the party had come close to matching the 82,000 of the SNP, predictions of a triumph for Ed Miliband next May would have come thick and fast.

Instead, Labour in Scotland is enduring another of its little local difficulties. With Johann Lamont's sudden if unsurprising resignation, the party must look for a seventh leader in the space of just 15 years. Its matchless reputation for incessant internecine warfare has meanwhile been maintained.

Quitting, a bitter Lamont describes an organisation regarded as a "branch office" by high-handed London colleagues, its leader marginalised when not ignored. Jack McConnell, one of her numerous predecessors, has described her treatment as "outrageous". Lamont's devastating central point is that those around Miliband neither understand nor care about devolution. For a self-styled "People's Party", it's not a pretty picture.

As to actual people, silence reigns. Labour, still obdurately identifying itself as "Scotland's largest political party", doesn't give out membership numbers.

Some truths can no longer be ignored. One, already a cliche less than six weeks after Scotland's vote, is that No's victory was Labour's defeat. First and foremost, Glasgow and other former heartlands chose independence. According to one poll, meanwhile, 37% of those who previously voted Labour voted Yes. In surveys of voting intention since, the party has been clobbered.

You could, if loyal to Labour and daft, be sanguine. You could tell yourself a new leader means a new start. You could say that popularity and members come and go, that Holyrood elections and Westminster elections are different things. Perhaps you might convince yourself the lost voters will return when another Tory government threatens. When has that one ever failed?

If the party was a person, we would be talking about personality disorders. A failure to address reality would be a clue. The Labour that took a hiding in the last Scottish elections conducted the referendum campaign as though oblivious to a changed mood, as though incapable of believing "lifelong supporters" could desert, as though a pact with Tories and bankers would produce no anger. Lamont, for one, has been left with no choice but to face the consequences.

Yet some of her former adherents still attempt to mock those who voted Yes. Those voters are instructed to "move on". They are told they were deluded or deceived. In its infinite stupidity, the party has refused to ask the obvious question: how could anyone, treated in that fashion, return quietly to voting in the old way?

The coalition on which Labour was founded did not include Tories or big business. The party was created by trades unionists. Modernisers might disdain the fact, but "the link" is old and intimate. It's what gives the party its very name, never mind its reason to exist. What's more, as often as not, those millions who pay their union subs still foot Labour's bills.

Miliband does not wish to be depicted as "the prisoner of the unions". The unions, meanwhile, know that one old truth is these days a simple fact of life. For employees still in union membership, the idea that Labour is their only choice is a hoary joke. Why should a Green voter see money going to support Miliband? Why should an angry Yes voter, recalling Scottish Labour's behaviour, give a penny to keep it in the game?

Last year, Miliband argued that the connection between political funds and Labour Party affiliation fees for individuals need no longer be automatic. He had his own ambitions for a "mass party" and useful headlines in mind. Scottish trades unionists who voted Yes have other aims in view.

Among these people there has been a groundswell since the referendum. Given the behaviour of Labour and certain big unions in Better Together, real anger has mounted and a political levy boycott has been gathering pace. The unions that endorsed the No campaign with little thought and precious little consultation are paying the price. In hard cash.

Like Scottish Labour, they have weakened themselves, perhaps irreparably, by their choice of causes and friends. Westminster and Miliband's fate have mattered more than respect for members. There might be nothing new about the failure of unions to represent diverse views. There is something new going on, however, when people decide that the movement itself is tainted by association. Lamont has all but admitted as much.

Labour and friends in the GMB, Usdaw, CWU and others knew - or should have - the referendum was liable to cause them immense damage, yet they pressed on regardless.

Who will be won back to Labour next May? How fertile is Scottish ground now for a trade union movement that has problems enough? The sanguine and stupid, the paid operators and the party hacks, will go on holding out their crumbs of hope to diminishing audiences of the faithful. But a historic unravelling is taking place. The second casualty, after truth, is the labour movement.

With Lamont's departure, another truth will need to be addressed: old things in Scotland are being destroyed before the new has been properly born. But we'll cope.