There was never any doubt that Jim Murphy was the best candidate for leader of the ­Scottish Labour Party.

No disrespect to Neil Findlay and Sarah Boyack, but personality and charisma are important in politics and the former Labour defence secretary has heaps of both, plus experience of Cabinet politics in Westminster.

We've always said that Labour sends its best people to Westminster. Well for once, one of them has come back, and that is surely positive. There, I've said it: Jim Murphy is a good thing for Scottish politics.

He has a dark side too, of course. He supported Trident, Iraq, tuition fees, Blairite reforms to public services in Westminster, etc etc. But Murphy is, above all, a gifted opportunist. He has adapted his political principles to the task of leading Labour in a country where the political culture is overwhelmingly social democratic. (Whisper it, but Alex Salmond did the same with the SNP).

Listen to the victory speech New Jim made yesterday. He hammered on and on about two things: patriotism and social justice. He condemned the fact that poorer people live nine years less than those living in better-off constituencies. "Our driving purpose is to end that inequality once and for all," he said, channelling Wendy Alexander circa 2000.

Then he appealed to Yes voters to recognise that they have "more values in common with Labour than with the political leaders of the No campaign". Well, precisely. Perhaps this was a veiled criticism of Alistair Darling and Better Together for getting just a little too close together with the Conservatives.

Cue nationalist jeers that all this is rich coming from a former Blairite who was just as keen on standing shoulder to shoulder with the class enemy. And who opposed - initially at any rate - more powers for Holyrood. Murphy's support for the Smith reforms was certainly belated, but he now sounds like an enthusiast for fiscal autonomy. Though how he expects the devolution of some income tax powers to spark an economic boom in Scotland when the economy is shrinking is a mystery.

In fact, it is now very difficult to know Murphy's position on just about any issue you care to name because he has apparently abandoned nearly everything he used to stand for. He has dropped his support for university tuition fees - at least in Scotland He wants high taxes on the wealthy and more resources for elderly social care. He doesn't appear to want to dump the "something for nothing" measures like prescription charges and concessionary bus fares, or if he does I've missed it.

Is there anything on the left agenda Murphy doesn't now accept? Well, nuclear weapons obviously, since he still supports renewal of Trident. But otherwise, he speaks just like a Scottish social democrat.

When Murphy first put his hat in the ring for leader, I said he would have to undergo an ideological brain transplant to lead the Scottish Labour Party. Well, the operation appears to have been a success. For now, at least, we are looking at New Jim - Man Of The People and True Scot.

Problems may arise for New Jim in Westminster, however - assuming he remains an MP. If Murphy continues to follow the Labour whip he may have to vote on immigration controls, benefit caps and on austerity measures that may belie his leftism in Scotland. But there isn't much going through Parliament right now anyway and after the General Election in May is another country.

In the unlikely event that he returns after the General Election you could see Alex Salmond and Murphy in the same coalition. If the SNP hold the balance of power they have sworn to back a Labour government at least on confidence and supply. Alex and Jim joining hands in fraternal solidarity with Ed Miliband - that really would be a sight to see.

But the New Jim poses an immediate problem for the SNP and the Nationalist left in Scotland. They can't go on merely reciting his voting record in Westminster when he was part of Blair's government; people change - the voters accept that. And they have short memories. Murphy cannot just be routinely dismissed as Red Tory Scum unless or until he starts to behave like Red Tory Scum, and I don't think we will see that for a while. He is too quick on his feet.

Even before he became leader Murphy was making the political weather on the left. For example, he arguably forced Nicola Sturgeon to agree to restore the 50p rate of tax whether or not it is restored in England, which could be a real fiscal headache for her finance minister in future. Murphy's adoption of higher taxes on the rich may have been opportunistic - it certainly wasn't how he regarded taxation when he was a Blairite. But in a sense it doesn't matter: he took the initiative.

We are now in the odd position of having two rival parties who sound as if they are fighting on almost exactly the same political territory. Murphy and Sturgeon are liable to find themselves giving almost identical speeches at conference time - though of course the SNP leader has the difficult job of actually living up to her social democratic principles in office.

Murphy has made clear he will condemn failures in social care being caused by "SNP cuts" and challenge the Scottish Government over an education system that is failing working-class young people - working-class representation in higher education is as bad as it was a century ago.

Mind you, doing anything about working-class under-achievement is another question. But in crude political terms there is a strong agenda of social inequity now for Murphy to use against the Scottish Government. This is what an opposition is for.

Though, significantly, in his BBC Scotland hustings debate last month, Murphy refused to say that he would definitely lift the council tax freeze, unlike his rivals who said the cap was regressive and distorting. Murphy is, above all, a politician, and he realises that tax rises - on any but the rich - are still toxic in Scotland, despite the much-vaunted social democratic political culture.

Murphy will have a honeymoon period and the only way is up for Labour under his leadership, if only because it is almost impossible to see Labour going any further down. The latest opinion polls are appalling for Labour, showing the SNP on course for more than 40 and possibly even 50 seats at the General Election.

However, no-one really believes that is possible. And if Murphy only claws back 10 points or so in the polls, then he saves a lot of seats. Remember, the SNP only won six MPs in the 2010 General Election against Labour's 41 in Scotland. There are no Labour seats in Scotland where the SNP is less than 10 points behind.

The expectations on the SNP are simply too great to be delivered, and that is likely to be New Jim's lucky break. It's always best to buy at the bottom of the market.