As the British election approaches -- the vote is on Thursday -- opinion polls in Britain suggest that support may be shifting to the Tories. Surprises are possible: Many voters say they're undecided, and small changes in voting intentions, acting on closely contested seats, can move the balance of power in Westminster a lot. Still, at the moment, neither Labour nor the Conservatives seem likely to get a parliamentary majority.
That's awkward in a system that takes one-party rule for granted -- but it gets worse. Consider a very plausible outcome. England rejects Labour and elects a Tory majority. Scotland also rejects Labour, and elects the Scottish National Party in a landslide. Thus, the United Kingdom gets a Labour government.