You should hear what Alex Salmond's enemies say about him, behind his back. "He's the consummate political operator," says one opponent of Scotland's first minister from his vantage point in another party. "Articulate, charismatic, with a particular ability to conjure up a phrase that captures the public mood. Where he's especially good is in talking to the UK audience, sounding like the reasonable voice of Scotland. He was on The One Show the other day and I bet English people were watching it thinking, 'If only we had a politician standing up for us the way Alex Salmond stands up for the Scots'." Such is the damning assessment of one of those dedicated to removing Salmond from office.

Not that that front-rank Scottish politician is deluded enough to think his party has a chance of toppling Salmond from the pinnacle of Scottish politics any time soon. And pinnacle is no overstatement. The Scottish National party was re-elected in a landslide in May, winning the very overall majority Scotland's electoral system was designed to render impossible. Salmond's party is united and disciplined behind him, and his putative rivals trail far behind in the opinion polls, mere minnows to his shark. This week the Times anointed him Briton of the Year, a surprising accolade for a man who does not readily describe himself as a Briton at all. To my mind, Salmond has long been the most naturally gifted political performer in these islands, unchallenged for that title since the departure from the scene of Tony Blair. Even in Blair's day, Salmond came very close.

What's his secret? He has intellect, a former Royal Bank of Scotland economist's grasp of numbers and a wide hinterland that enables him to talk confidently about nationalism and its place in the forward march of history. He learned long ago the Ronald Reagan maxim that the successful politician owns optimism and the future. Successive election campaigns have boiled down to one essential theme: that there is no limit to Scotland's possibilities. Indeed, "Yes, we can" was the SNP slogan in 1997, long before anyone had heard of Barack Obama.

As for that knack with an easily understood phrase, it has not deserted him. Criticising George Osborne's economic policy – earlier than most – Salmond said Scotland needed a "plan McB". Cheesy perhaps, but memorable. He is also skilled in the low arts of politics, cunning enough to have pulled off that hardest of tricks, the comeback. He quit the leadership in 2000 amid some mystery – only to roar back into the top job four years later. That break apart, he has led the SNP since 1990, a more than two-decade tenure of positively North Korean duration (indeed one that outstripped Kim Jong-il).

Experience is perhaps his biggest asset. The new leader of the Scottish Conservatives, Ruth Davidson, was 12 when Salmond, 57 on Saturday, first led his party. Labour's new boss, Johann Lamont, is older than Davidson but she too has only a fraction of Salmond's experience and none of his profile. None of the leaders of the other main parties in Scotland "is even in his league", one opposition politician admits.

Is this absence of serious rivals the cause or consequence of Salmond's dominance? A similar question attended Blair in his pomp too. Was Blair merely lucky to face a series of dud Tory challengers – Hague, IDS, Howard – or was the lack of talent among his opponents a function of his supremacy, a reflection of the fact that his adversaries had no idea how to oppose him? In Salmond's case, there is hard evidence for the latter view. He has challenged them to come up with a second question to appear on the ballot paper when Scots vote in the promised referendum on independence. They have not, so far, responded, reducing their role to that of mere naysayers to independence: the parties of no.

The more dominant he becomes, the more dominant he is likely to remain. Scottish Labour, for example, might stand a better chance if one of its former UK cabinet ministers took over. But Douglas Alexander, Jim Murphy and others have probably concluded that the prospects of Labour taking power in Edinburgh are even gloomier than in Westminster. So they stay away, leaving the way even clearer for Salmond.

Intriguingly, the only possible obstacle Scottish political hands can see in Salmond's way is his cherished dream of independence. No matter how high the SNP climbs in the polls, public support for a Scottish break from the UK remains stubbornly pegged at about 38% or lower. If Scotland votes no, that could surely break the Salmond spell. It would certainly cause restlessness among those SNP activists who have so far accepted the leader's gradualism.

Salmond has seen the risk, of course, and plans a second question of his own, offering independence-minus, or "devo-max", a supercharged form of autonomy that stops short of a full rupture. That would surely pass. Such an outcome might even suit Salmond better than independence, for his appeal rests, in part, on his status as the underdog, the plucky (Scottish) man against the mighty (London) machine. All-powerful first minister he may be but, as long as he is campaigning for independence, rather than achieving it, this appeal remains intact. For Salmond, truly the journey is as important as the destination.

Those of us watching from the outside, especially those who prefer a Britain that includes Scotland, are not mere observers: we have a stake in all this. Salmond's dominance means that, when the referendum battle is finally joined, defenders of the union will have no voice to match that of the independence campaign. The Scottish Labour, Tory and Lib Dem leaders are too weak to head the 'no' effort. Some suggest a figure outside politics – Alex Ferguson? – or an elder statesman, such as Gordon Brown. But both bring complications. This is a more pressing question than it might seem. Salmond has promised a ballot by 2015. As things stand, despite the polls, there is at least a chance that it could be settled in favour of independence by sheer force of personality. Salmond may be the Times's choice of a great Briton, but his ferocious talent could yet prove to be Great Britain's undoing.