What happens when voters with 'nowhere else to go' have somewhere else to go?

From the fateful day in May that the Lib Dems turned their back on the possibility of a progressive coalition and entered a Tory-led government instead (admittedly partly as a result of the antics of Labour neanderthals such as John Reid and Tom Harris), I've been fairly pessimistic about the impact on Scottish voting trends. It seemed obvious that Labour would prosper as the default anti-Tory option for many Scots. But there is a more positive way of looking at it as well, as indirectly identified by Fraser Nelson in the Spectator's Coffee House -

"Some 51 percent now disapprove of the coalition government. Who do they vote for? Coalition has granted Labour monopoly control of opposition."

Not everywhere it hasn't - and in these parts, of course, that 51% figure is a lot higher. The opposition ranks (in Westminster terms) have indeed been squeezed in Scotland - but to two, not one, and that presents an opportunity for both opposition parties. I suspect in many parts of Scotland, the SNP is still a more attractive option than Labour for disaffected Lib Dems (and indeed Tories). Nelson is probably right - for once - that the 'where else do you go?' logic will soon see Ed Miliband in a commanding position south of the border, but it's just possible the effect in Scotland will be somewhat more complex.