Back when journalists dictated words over the phone, special people stood between writer, newspaper and disaster.

It fell to copytakers to turn bilge into English. They also had a knack for deflating the hack who imagined he was hitting his stride. "Is there much more of this?" a weary voice would ask.

Just at the moment, most of us recognise the feeling. Another three and half weeks of this? The election campaign already feels like an experiment in theoretical physics that has gone badly wrong. Whatever became of reality? According to the best estimates, it lies 25 long days in the future. In some quarters, its reappearance is liable to come as a profound shock.

Yesterday, Labour brought what used to be known as big guns to Scotland. We got a pair of Eds for the price of a Jim. Below the border, Ed Miliband is beginning to look almost like a plausible candidate at last. In these parts, he faces the kind of tumult that could define his leadership, his party, and - even if his luck is in - his premiership.

Answering questions in Edinburgh, Mr Miliband did not try to deny that there is a big gap, the kind usually called a chasm, between Labour and the SNP. He did seem to think, however, that the problem is best addressed by the kind of campaigning we saw before the referendum. Throw figures around; frighten the lieges; stick to the line that Scotland is too weak to be anything other than dependent. What could go wrong?

As it happened, the question had just been answered by a YouGov poll for the Times that was causing jaws to drop from the Northern Isles to London. It wasn't the fact of an SNP lead, even a big SNP lead, that caused the astonishment. It was the utter demolition of received campaign wisdom implied by the numbers.

Almost everyone believed that Labour would have begun to claw back a bit of ground in Scotland by now. Few of those paid for opinions questioned the belief that Jim Murphy's performance in TV debates deserved good reviews. YouGov said instead that the SNP led Labour by 49 per cent to 25 per cent, that the former was up three points and the latter down by four. Mr Murphy had meanwhile "won" the STV leaders' debate according to just 13 per cent of those asked.

In other words, Mr Miliband had not picked the happiest moment to visit his Scottish colleagues. In fact, he had landed in the middle of a catastrophe. Almost four months into Mr Murphy's leadership, things had grown worse, not better, a fact that raises some questions in its own right. The comical petulance of those deprived of their politics-as-usual is now irrelevant. The UK General Election hangs on Scotland: get used to it.

As things stand, Mr Miliband is liable to emerge with the largest party at Westminster, but one incapable of forming a government unaided. He has rejected a coalition with the SNP, an act of decisiveness rendered superfluous by the fact that a deal was never offered. Nicola Sturgeon has meanwhile reduced the Labour leader's room for manoeuvre to almost nothing. Any confidence and supply arrangement, she said on Thursday, would "require the non-renewal of Trident".

Labour claims it will not budge on that. In fact, in the words of Dame Anne McGuire, former MP for Stirling, "a Labour government won't do any deals with the SNP on this issue or any other issue for that matter". With Mr Miliband facing Tory smears over his reliability as a happy nuclear warrior, Trident is again totemic. So how does he hope to form a government or, for that matter, to govern?

If Labour means what it says, a minority administration is inevitable. It means, in turn, that the SNP will support Mr Miliband - or not - on an "issue-by-issue" basis. The Liberal Democrats are unlikely to be able to help him out. Plaid Cymru takes the same attitude towards Trident as the SNP. Northern Ireland's Democratic Unionists will not be able to make the numbers work. Either Mr Miliband comes to terms with Ms Sturgeon, risks losing much of his programme in the inevitable horse-trading, or he begins to plan for another general election.

Trident is, in the jargon, a "red line" for the SNP. Anyone who still thinks its leader can be bought off is dreaming. Quite how a confrontation will arise remains to be seen, however. It might be over a renewal bill, the defence estimates, or conceivably an entire budget. Labour likes to maintain it will dare the Nationalists to oppose its "progressive" policies. How will it feel about depending on Tory votes for the sake of Trident?

In any case, the idea that parliamentary Labour is committed to the weapons system has yet to be tested. The party has never been united over the issue, but there are signs - nothing more - that a new intake might be less keen than Mr Miliband to supply Nato with two per cent of its nuclear arsenal. A survey of 79 prospective candidates carried out by CND and published last month showed that three quarters want Trident scrapped. True, only 79 responses were gathered. True, it was a CND study. Still, plain sailing, as it were, is not guaranteed.

More will be at stake, in any case, than nuclear weapons. Ms Sturgeon has not made an issue of economic policy for nothing. Despite Mr Murphy's born-again egalitarian rhetoric, despite Ed Balls promising to "end austerity" with his first budget, Labour signed up to George Osborne's £30 billion cuts programme in January. This issue, too, is liable to become fundamental.

What else? The trouble with issue-by-issue politics is that there is always another issue. Dozens of SNP MPs will not be turning up at Westminster simply to nod through Labour legislation if the proposals fail to follow the course Ms Sturgeon is charting. How would Mr Miliband cope with that? Would he bother to try?

Sterling has endured a bad month as markets fret over uncertainty. Labour has done nothing to calm the jitters. Some of the nerves have to do with plans already announced by Mr Miliband and Mr Balls to reform the banking and energy sectors, but doubts go deeper. Like everyone else, investors just want to know what lies ahead. Labour has only managed to tell us what won't happen, supposedly, where the SNP is concerned.

The Fixed-term Parliaments Act creates obstacles to another election before 2020. A government would need to lose a vote of confidence, or oversee a vote for dissolution by two thirds of MPs. The Tories might be busy with a leadership contest and less than keen on another campaign. But that makes the temptation for Mr Miliband all the greater. It could be his only hope of escaping the trap created by Scotland's voters.

The flaw in the idea is obvious. If voters here are not for turning, the issue of Scotland remains. One election or a dozen: it will make no difference until received wisdom is abandoned. There's much more of this to come.