Cameron has whipped British nationalists into a frenzy, Miliband has resorted to monument raising, the Independent is penning wartime-style editorials, Brown rallies the faithful, plurality is equated to crisis, the centre cannot hold and there are only hours to save the union. The British political establishment is reverting to full on apocalyptic mode, in what may yet become a seasonal habit.

Taken as part of a longer view: such an orgy of odd behaviour has at least in part been fuelled by the fact that Scottish politics is front and centre of a UK general election, rather than taking up its traditional background role.

It’s a measure of just how much the country has changed since it last went to the polls. In the course of five years we have swapped an era of Scottish Labour MPs leading the UK government, for a home grown politics that seems to take people with it. The difference between the leadership of Nicola Sturgeon and Gordon Brown is a fitting representation of the scale of this transformation.

As the remarkable rise of Sturgeon has demonstrated Scotland remains a political exporter. A century ago, Liberal grandees like Churchill or Asquith would pop up to their Scottish constituency from time to time, but rarely had to check in with the electorate to land the thumping majorities guaranteed them.

Two competing and often contradictory battles have taken place ever since: the search to be the party that ‘speaks for Scotland’ and to be the party that charts the course of the British state. A decades long political lesson has shown these two aims to be incompatible. On Thursday, the settled will: that Scotland would always want around fifty grey and nameless Labour MPs sitting for it in the commons, is likely to be unsettled. Where once a generation of surly, intellectual Scottish strong men dominated the UK party (later Paxman’s ‘Scottish Raj’) it is now devoid of both charisma and ideas in the north.

In 2010, the SNP were thought to be on the wane, an embattled minority government, grappling with controversies that were hard to test in Scotland’s limited public arena. Scotland, in Jim Murphy’s words, ‘had come home to Labour’. Today, it is the presence of Nicola, the definitive first name politician, that means the SNP could sweep the board as it did in 2011. Her almost presidential campaign, while not seeking office, is the perfect vehicle for a Westminster contest. The First Minister’s ability to speak for Scotland as an already incumbent stateswoman, has provoked fascination, terror and delight in equal measure.

Never before has Scottish politics received such extensive exposure from UK media. Never before has a leader of the devolved Scottish Government gone up against a prime minister and leader of the opposition and found ready support south of the border. Meanwhile, Labour are still fighting yesterday’s battles, unable to recognise that for all the risks of hubris and post-election compromise, Scotland has found its woman.

Big questions for Britain now follow in her wake. Will a British public tolerate reversion to a more narrow set of aspirations once this is all over? Will they forget leadership debates that briefly offered a glimpse of the country as a modern, diverse, European social democracy? Most importantly of all, will this brief vision of plurality be written off as part of a constitutional crisis? Or is it here to stay?

The pertinence of these question will only increase in the frenzy of the coming week. It’s a tension that could be definitive. For alongside the addition of new voices and styles of leadership there remains the dull masculine nature of a winner takes all contest: of Cameron getting pumped up and ‘hell yeah I’m tough enough’ Ed. Britain’s prime ministerial system of government demands it, but the country is facing its own critical choice: whether to remain a macho society where success is measured through the mean and narrow ambit of who gets first past the post, or whether a more rational society, which can probably only be the result of a more rational system of government, would prioritise the needs of more than just the 1%. That success is not just about who comes first, about whose party has a bigger minority, but about who can build a consensus that represents what the people have asked for.

There is of course something odd about the notion of one party speaking for an entire society. This applies as much to the SNP as it does to its UK counterparts. If Scotland has become a whole lot bigger and grown up, if it has become stronger, it is not because it has become more singular.

At election time, this vast, diverse, country called Scotland is often referred to as though it is one great homogenous Westminster constituency. A safe seat of five million that switches loyalty with a plodding generational pace. The Liberal heartland became the Tory’s, before its votes were overwhelmingly cast for Labour. The picture is crude and simplistic. It reflects an electoral system that has allowed those parties to dominate the tightly packed parliamentary seats of central Scotland and little else.

Perhaps in ages hence historians will look at 2015’s constitutional crisis and reflect that it was first past the post that broke the union. Over two generations, the issue of who has a mandate to govern Scotland has turned into a deep political fissure. Had diverse Scotland been represented more accurately at Westminster it is perfectly possible that there never would have been a referendum on independence.

What’s fascinating is that so few commentators, particularly in London, could comprehend that extending the life span of the union would do anything other than destroy the SNP. Deaf to the notion of Scotland as a complex society, it assumed that the rush of nationalist fervour would become a marginal activity, more analogous to England in ’96 than Scotland in ’97. Casting a vote that mattered in September has not turned Scots into teary eyed ethnic drones that will vote for whoever clutches the saltire with the most conviction. These were people who voted for change with the might of corporate Britain forecasting imminent disaster if they did so. That has hardened and radicalised them for a vote in which only the brute force of big party machines can win through.

At this point, the metropolitan commentariat might want to take note: the only event that can defeat the SNP is independence itself. This perfidious union means that Scotland needs the SNP, because Westminster is one of the few outlets for its national life in which it is treated like a single bloc.

In 2003, when Scotland made its first noticeable step away from Labour on the back of the Iraq war, Holyrood played host to a ‘rainbow parliament’ in which smaller parties had an enlivening effect on a what had been a lamentably dull chamber. In contrast, at Westminster in 2015, there is no talk of rainbows. Rather this vastly more powerful institution is wrapped in the dark clouds of potential crisis. Robbed of its traditional prime ministerial system of thumping single party majorities the chamber is said to be ungovernable, polarised and illegitimate. Ironically, the old question of who has a mandate in what nation has been inverted. Independence was always going to be inevitable when England woke up to its own desire for it.

Scotland is actually more comfortable leading than its fondness for self-deprecation gives it credit for. In these islands it has often been Scots who have dreamed, imagined or led a change of course for our neighbours to follow. If not quite a nation of vanguardists we are at least so ill disposed to being led that in the right circumstances, audacity can be found in abundance. While the SNP are able to channel this, they will remain a formidable political force in the UK: but if they forget it, they’ll go the way of all the other parties that once claimed to be ‘stronger for Scotland’.