LIKE most of the journalists glued to their Twitter feeds last week, I thought Labour's Jim Murphy did pretty well in the Scottish leaders TV debates.

He imposed his personality a bit too forcefully sometimes but seemed to get his message across that Labour had taken big strides to the left, calling for tax increases on the wealthy. He delivered his prepared lines flawlessly: like the one about Sturgeon having gone from the Yes campaign to the "Mibbes Aye, Mibbes Naw" campaign. People on social media attacked him as "creepy Jim" - but that's what they always do.

So it came as some surprise to learn that, once again, the mainstream media had got it completely and utterly wrong. At least according to YouGov's post-debate opinion poll, which recorded that Nicola Sturgeon walked it by a mile with 56% thinking she did well in the debate.

Jim Murphy was trailing behind the Tory Ruth Davidson at 13% and the Liberal Democrat Willie Rennie became Mr 1%. His rating was within the margin of error.

Most of the press ignored this and continued to insist that Jim had "blown a hole" in the SNP's tax policy; that Nicola Sturgeon had been "stunned" by the Edinburgh audience jeering at her refusal to rule out another referendum. Some even suggested that Ed Miliband's visit on Friday would capitalise on Jim Murphy's debating success.

This is getting just a little disturbing. It's not healthy when the nation's press appears to be living in a parallel reality - aside, that is, for The National, which invariably supports the SNP. In most of the UK media there is a state of bewildered incomprehension about the irresistible rise of the SNP.

The latest authoritative YouGov poll on voting intentions, conducted during and after the debates, registered another increase in the SNP's humungous lead over Labour. Nearly half of Scotland's voters, 49%, it recorded, are now preparing to vote for the SNP, with Labour back at 25% . This is off the scale even for the SNP

Of course, these are only opinion polls and there is still nearly four weeks to go. Fortunes can change rapidly in the age of social media. But this is beginning to look like one of those generational shifts in Scottish politics.

Back in the 1950s, the Conservatives dominated Scotland. Then Labour took over in the 1980s, destroying the Tories as a political force and wiping out their MPs in 1997. Now, it could be, that the SNP are doing the same to Labour, with polls suggesting they will return over 50 of Scotland's 59 MPs

Yet only seven months ago, Scottish voters decided by a comfortable majority to remain in the United Kingdom. No wonder UK politicians and commentators are perplexed and claiming that appearing in the press that the Scots have "gone mad". The normal rules of UK politics no longer seem to apply in Scotland any more.

One reason Labour and the Tories have been pole-axed, though, is purely presentation. They had hoped to marginalise the SNP by equating it with Alex Salmond, a Marmite politician who is not popular in England, and is regarded with some suspicion in Scotland.

But sneakily, the Nats exchanged him for Nicola Sturgeon, who carries none of his baggage, is personable and has a rare ability to connect across gender and even political boundaries. Nicola Sturgeon's appeal is now almost above politics - straying into the kind of affection normally associated with celebrities or members of the royal family. Her net approval rating is plus 48 against minus 18 for Jim Murphy and minus 46 for Ed Miliband.

Sharp, intelligent, confident, down to earth - her image chimes with how modern Scots like to regard themselves. "Nicola", as everyone calls her, has the gift of being able to convey a political message simply by being there. This means she doesn't always need to engage in the rough and tumble of conventional political argument.

So, when Jim Murphy scored some real hits in the debate, over her equivocation about calling another referendum, it didn't seem to damage Nicola Sturgeon. People seem to have decided she is trustworthy and that Jim Murphy, well, isn't.

Ed Miliband also failed to engage with the Scottish voters last week. His "SNP austerity bombshell" - the claim that fiscal autonomy (FFA) would lead to a £7.6bn black hole in Holyrood - is too reminiscent of the right's perennial arguments against Labour. They even use the same image of a "tax bombshell" in their election literature that the Tories used in 1992.

Labour may have the Institute for Fiscal Studies on their side, but for many Scots the austerity bomb seems like a recapitulation of the Better Together campaign arguments from last year against independence. Indeed, Jim Murphy resorted on Friday to the claim that pensions would be hit by FFA. Sturgeon angrily accused him of scaremongering.

It has to be said that the SNP have been fairly weak on the finances of fiscal autonomy. The party say that the immediate threat is from Tory cuts, but they haven't effectively rebutted the charge that there would be a financial shortfall if all tax-raising were to be devolved to Holyrood.

However, this doesn't seem to matter very much. FFA is a complex argument at the best of times and there is anyway little prospect of fiscal autonomy or devo max actually happening any time soon because the UK parties won't vote for it.

What will happen is that the Barnett Formula, which calculates Scottish spending as a fixed share of the UK budget, is effectively being phased out. Jim Murphy said last week that he would support the Barnett Formula "now, tomorrow, forever". However, he must know that, by 2019, if Barnett exits at all, it will only be used to calculate one-third of Scottish spending.

This is a contradiction the SNP have chosen not to exploit, possibly because phasing out Barnett poses fiscal problems for them also. But the point is that there is no longer a fiscal status quo. Things are bound to change when Holyrood starts raising most of its revenue directly under the Smith reforms.

Elsewhere, Labour seem to have toned down the argument that "a vote for the SNP is a vote for the Tories" since the disastrous smear campaign of last weekend. The "secret memo" claiming that Nicola Sturgeon had said she wanted David Cameron as PM has been thoroughly discredited. The affair rebounded on Labour for having rushed to judgement.

Labour's retread of the Better Together lines from the 2014 referendum may seem desperate, but that's pretty much all they've got at the moment to combat the runaway Nats. They have had to try to appeal to older and middle-class No voters rather than their traditional working-class support, which has defected to the SNP.

And, buoyed by the opinion polls, Sturgeon now seems less insistent that her only aim in life is to put a Labour prime minister in Number Ten. Indeed, last week she appeared to be ruling out a "confidence and supply" pact with Ed Miliband if he proceeds with the renewal of Trident.

She hasn't said that she would ever vote down a Labour Queen's Speech, of course, but this is a significant rhetorical shift. The SNP is no longer apologising for being unable to form a government in Westminster and is downplaying its claim that it will only vote with Labour.

Gaun yersel' seems to be the current line, and why not? The voters of Scotland seem to have fallen in love with Nicola Sturgeon; she is adored. And while love affairs with politicians rarely last, this one only has to endure four short weeks.