In Edinburgh, Alex Salmond walks with the swagger of a man who feels that these could be the last days of the Union.

Edinburgh
Throughout my time in Scotland I was asked, again and again, the same question, rhetorically or otherwise: can anyone stop Alex Salmond? At present, the Scottish National Party leader and First Minister seems pretty much unstoppable. A cult of personality exists around him. He is the Big Man, without political equal or rival in his homeland. He moves with the buoyancy and swagger of one who feels that these could be the last days of the United Kingdom.

Many of his old adversaries - Donald Dewar, Robin Cook, Jim Wallace, Jack McConnell, Gordon Brown - are dead or in retreat. He is the leader of the new establishment in Scotland, a formidable machine politician with the stamina, tenacity and opportunism of a Latin American charismatic. He is a kind of pale-faced, northern European Lula da Silva and his pro-market social-democratic populism, as with Lula's in Brazil, is proving to be very appealing to a Scottish electorate that had grown weary of Labour's client state and its entrenched culture of cronyism, and which long ago gave up on the Conservatives.

“When a Scotchman sets out from this port for England," Dr Johnson once said to his biographer James Boswell of the Firth of Forth seen from Edinburgh Castle, "he forgets his native country." It was never so for Salmond: during his years of exile in London as an MP he did not stop believing that he could break the British state and create an independent Scotland. For Salmond, Scotland was a proud nation without a state, if not quite a colony of imperial England's then an inferior partner in an unhappy union: exploited, condescended to. This was the grievance that fired his restless ambition and gave definition to his complaints. In politics it always helps to have conviction, as Margaret Thatcher did, and to believe in something big; to have a project and a clear and defined enemy. For Salmond, the enemy is England and the British state.

The SNP leader has never been in a hurry. He is a gradualist. He knows where his journey ends and where he wishes to plant his flag of victory - through the heart of the last British prime minister. But he knows, too, that most Scots remain sceptical of full independence, which is why in these early skirmishes over the 2014 referendum he is being flexible and pragmatic, cravenly shifting his position on the EU and the euro and exploring the possibilities of a third way between the status quo and independence, between a straight yes and no.

He operates with the freedom of one who knows that there is no one commanding opponent to challenge him - at least not yet. David Cameron, so nimble in a crisis and so fluent, is the only politician in Britain who could be his match but he has larger problems: in spite of his Scottish surname, he knows that as an upper-middle-class English Conservative - Eton-educated and plummily poised - he would in all likelihood be received with derision in Scotland as and when the time came for him to go up against Salmond in the pulpit.

Then there is Gordon Brown, who keeps his silence at home in Fife. "He's lost confidence," I was told by one of his former aides. "He keeps asking himself - 'What was that all about?' He can't quite believe what has happened to him and to Labour." Brown holds Salmond in as much contempt as Cameron and George Osborne do. But they have power and he doesn't; they ultimately won and he lost.

The scale of the defeat in the Scottish Parliament election of May 2011 was a shock from which Labour has not recovered. The proportional voting system was set up in Scotland - or rigged, if you will - to prevent any one party from achieving the kind of majority won by the SNP, and with it a mandate to hold a referendum on independence.

“The SNP victory took me completely by surprise, which feeds into a more general lack of awareness of what was happening in Scotland," Johann Lamont, elected as leader of the Scottish Labour Party in December, told me when I visited her at Holyrood. "We did not recognise what was happening to the Labour vote nor the way in which the SNP were positioning themselves, being both left, right and centre. And actually, they were putting a triple block virtually on the question of independence. It is their only policy, but that wasn't their message . . . We did not recognise the scale of the challenge in taking on a party which had constructed a coalition that included Tommy Sheridan and Brian Souter [a businessman and Christian fundamentalist]. So there is no politics there actually. This is all about identity and who is Scottish. I don't think in all honesty the Labour Party ever managed to include someone from the ultra left [Sheridan] and someone who is a right-wing homophobe [Souter]. Yes, you can strike coalitions, but if they are based on principle and politics."

For Lamont, Salmond is not a social democrat: he's a single-issue opportunist. "Are they a social-democratic party? Some of them are. Alex Salmond isn't. I think he said: 'I don't have a problem with Thatcher's economics, it was the social consequences I have a problem with.' Why would you make a distinction between the two? How can you separate off a decision to destroy the mining industry and then be sad because the mining communities have been destroyed along with it? One of his key advisers, George Mathewson, is a Thatcherite.

“What is my problem with David Cameron? He is a Tory. What is Alex Salmond's problem with him? He's English. I don't mind people being nationalists. I worry when it trips over into chauvinism and I'm frustrated when it becomes a substitute for arguing about real politics."

On the issue of independence, Lamont says that Salmond "wants it to come down to a fight between himself and the Conservatives. Alex Salmond wants to say that those who disagree with him are talking down Scotland, that our vision of Scotland within the United Kingdom is a conservative one. He is making arguments for us that we are not making . . . Alex Salmond wants to be Mr Scotland. But he is not trying to separate us all from some kind of colonial empire. It is a partnership. There will be a Labour campaign that will be making the point about why you would want to stay strong within the United Kingdom." As for Salmond, "If he gets into a place where it looks as if he is trying to fix things, or be canny or clever, or whatever, that will damage him. And a lot of people in Scotland don't agree with him."

We will find out for sure soon enough.