The Economist explains how the Scottish National Party (SNP) came to power in Scotland:
The disadvantage of first-past-the-post systems … is that by raising the threshold of parliamentary dominance, they contain the possibility of sudden, violent shifts in political power in the event of individual parties crossing that threshold. Despite its conservative electorate, SNP had espoused a centre-left creed since the 1970s. With Labour in government during the 2000s, it began to win over working-class voters, but had to compete for them with the Liberal Democrats. The 2011 Scottish election, however, was a perfect storm: blue-collar voters disillusioned with Labour, a Labour leadership complacent after decades of dominance in Scotland, the Liberal Democrats now in government and suddenly unpopular. The SNP obtained a good (37%) increase in vote-share but a spectacular increase (152%) in seat-share on the constituency list. It could form a majority government and set about making plans for the referendum.
And, if the referendum succeeds, it will throw off the normal balance of power in the rest of Britain. Many political analysts have predicted, given Scotland’s liberal bent, that the Tories will benefit (after Cameron is forced to quit, I suppose). Elaine Teng is skeptical:
Even if David Cameron managed to stay at the head of the Conservative Party, 2015 is surely Labour’s year, in part because Scottish voters will participate in that general election regardless of the result of the referendum. The actual separation of the Union—were it to occur—would be scheduled for March 2016, so the Scottish MPs would be elected as usual in May, take their seats in Parliament, and then leave in the spring of 2016, when their positions are abolished. Scotland’s participation all but seals the deal for Labour.
But what about after Scotland officially leaves? The Tories still wouldn’t have a guaranteed majority. True, Labour would lose 41 seats that they have been all but guaranteed; the Tories would lose only one. But the Tories have an additional factor working against them: United Kingdom Independence Party (Ukip), the far-right, anti-European Union, anti-immigration party that has surged to prominence in the past few years is already beginning to split the Tory vote. A Guardian analysis of 2013 local elections showed that in many districts, Ukip took enough votes away from the Tories to ensure that other parties won. And that wasn’t an isolated incident:A YouGov study showed that the Tories are losing six times more voters to Ukip than Labour, who are also gaining seats from the struggling Lib-Dems.
This is true, as far as it goes. But an independent England, Wales and Northern Ireland will be far more favorable territory for the Tories in the long run. It would be like removing Texas from the electoral map – giving the Democrats a new, structural edge. But the forces that have led to a possible Scottish secession have also led to the same feeling in England. Why should the English not determine their own future as well – instead of being bossed around by Brussels? Its possible England, post-secession, could withdraw from the EU – especially with its bigger conservative share of the vote – while Scotland tries to negotiate a way to stay. As I said: fascinating.