I love looking below the lid once the election results are in. Take the recent UK election. What does it tell us about the change in the “will” of the British electorate, if anything? And what does it portend for the future?

In terms of seats, what happened is:

• The Tories gained 24 net, enough to form a majority without the support of any minority party
• Labour lost 26 net
• The centrist Liberal Democrats lost 49, nearly wiping out the party
• The Scottish National Party gained 50

In terms of vote share, though, what happened is:

• The Tories gained a negligible 0.8%
• Labour gained 1.4% – still pretty unimpressive, but a bigger gain than the Tories, and yet they lost seats
  
• The Liberal Democrats lost 15.2%
• The Scottish National Party gained 3.1%

You may note that the above numbers don’t add up. Where’d those missing votes go?

• The UK Independence Party gained 9.8%
• The Green Party gained 2.8%

(Now the total vote is more than 100%, but that’s accounted for by losses across a variety of smaller parties, the most prominent being the British National Party, which was wiped out after losing 1.9% of the vote share.)

The SNP garnered 4.8% of the UK national vote and earned 56 seats, 8.6% of the total. UKIP garnered 12.7% of the vote and earned . . . 1 seat. UKIP earned half as many seats seats as the Ulster Unionist party, which only got 115,000 votes to UKIP’s nearly 3.8 million.

UKIP illustrates the reason why third parties aren’t supposed to exist in first-past-the-post systems: it’s supposed to be obvious that these votes are wasted – or, worse, would be strategically mis-placed, throwing a seat to the voter’s third-choice candidate rather than the voter’s second choice. It’s a rule of political science that’s been broken for decades in the UK, though – the LDP has long been in a position somewhat analogous to UKIP today, earning far more votes than seats.

But there’s an exception to that rule, and that is when there is a geographic “logic” to a party’s support. Such as is the case with the SNP today.

The SNP won an outright majority of Scottish votes. They also won majorities in many constituencies, and substantial pluralities in nearly all the constituencies where they failed to earn a majority. That’s why they have 56 seats, and UKIP has only 1.

Is that “fair”? Well, on one level of course it is – everybody knew the rules before the game was played, and the game itself was played by the rules, so by definition they have to accept the fairness of the result. But on another level, the real question is what the system is intended to achieve.

In a pure proportional-representation system, such as exists in Israel, for example, the Tories would have been the clear plurality victors in this election, but would have seen their seat count increase not at all. Labour wouldn’t have budged much either. Instead, all the movement would have been from the LDP to UKIP, the SNP and the Greens – because that’s what happened with the vote. And the new government would likely be a right-wing coalition of the Tories and UKIP – or, if that were politically unacceptable, either a government of national unity or a hodge-podge coalition of the Tories, LDP and SNP. (Such heterogeneous coalitions are far from unknown in proportional-rep systems.)

Of course, we don’t know what UKIP’s vote might have been in that scenario. If most UKIP votes in this election came from safe Tory or safe Labour districts, and the expectation was for a close election prior to the vote (as it was), then under a proportional-rep system those voters might have preferred to vote for their second-choice party rather than UKIP, rather than risk throwing the election to the third-choice party. This is precisely what happened in the recent Israeli election – Likud got a late surge from voters who might otherwise have voted for one of the smaller right-wing parties. (The same might have happened in this election, if voters were debating between, say, the LDP and the Tories voted Tory to prevent a Labour-LDP-SNP coalition government.)

But the question I wonder about is: under a proportional rep system, what would be the mood today in Scotland? The Westminster system under-weights the votes of geographically diffuse minority views. By the same token, it overweights the votes of geographically concentrated minority views. Which is more optimal for a given country depends very much on who you are trying to placate, who you are trying to convince to “buy in” to the political system.

If the essential question in British politics today is the constitutional status of the different countries that make up the United Kingdom, then the Westminster system makes it relatively easier for Scotland to demand that the question be taken up on terms that it dictates. If you look at the two-party vote in England, you will see how difficult it will be for Labour to form a parliamentary majority from English votes. But assuming the SNP doesn’t fade quickly, it’s not at all hard to imagine a future election in which no party forms a majority, and the only coalition partner for either Labour or the Tories have is either the SNP or each other.

Moreover, precisely because of the disparity in size, it is very difficult to imagine that the “Scottish question” could ever be as central to English politics as it is to Scottish. Which means that even if an English-nationalist or anti-federalist tendency takes hold south of Hadrian’s Wall, it’ll be a diffuse minority tendency, and likely be as efficacious as UKIP has been at turning votes into seats.

Does that mean commentators like our own Daniel Larison are right that this result points to the inevitability of Scottish independence, and that the UK is “living on borrowed time?” Maybe. But the history of the Bloc Québécois in Canada should give anyone making such predictions pause. In particular, I would argue that, if a plausible federalist solution exists, then a vote such as we’ve just seen is likely the necessary political predicate to achieving it. While it is true that anyone who voted “yes” on the referendum should logically vote SNP, the opposite is not the case – the mere existence of the SNP as a large bloc in Parliament gives substance to the notion that Scotland could get the best deal for itself by negotiating a high price for remaining in the union. And if that’s the case, then the peculiarities of the Westminster system that give an independent-minded Scotland an outsized share of seats are precisely the peculiarities that make it possible to hold the system together.

If the goal is to give a minority region like Scotland the maximum leverage to negotiate its terms of staying in the union, the Westminster system is pretty well-designed. Somewhere, John C. Calhoun is probably smiling.