While it's a being seen as something of a coup for UKIP, the defection of Tory MP Douglas Carswell to the party might turn out not to be the unalloyed joy that supporters think it is. For one a set-back in the by-election will signal yet again that voters are not convinced that the party is fit for Westminster. More importantly Carswell represents a different beast to those that Nigel Farage prefers to surround himself with. If Carswell stays and does well, by winning his seat back for example, then he naturally becomes a counter-weight to the great leader himself...
