I must say that the more I think of Douglas Carsewell's defection to the UKIP, the more it seems like a a game changer.
Up until now I've been of the opinion that the UKIP will fade away as we move closer to the election, and return a comparatively underwhelming 10% or 12% or whatever, and maybe one or two seats.
With Carsewell's defecting - perfectly timed to give them a boost, just when we were all starting to forget about them - and five weeks of continual media interest leading up to the by-election, and a likely trouncing of the Conservatives at said by-election, and the mouth-watering prospect of a UKIP having 10 months or so of grandstanding in the Commons, and the likelihood of Carswell / Farage being able to demand inclusion in debates and airtime, all bets are off.
It might not be a case of Scottish Independence, as the South East of England ceding from the union.
Alternatively, Carsewll will try to overthrow Farage and the party will tear itself to pieces and contest the election as the Real UKIP and the Provisional UKIP and vanish.