So I wouldn't hasten to claim that the mould of British politics has been broken. It's not clear that this represents anything more than a protest vote.
Or, perhaps, a popularity vote. The endearingly daffy Carswell against nobody in particular. What would have happened if the Tories had parachuted in a candidate with national recognition- Boris for instance?
If the big parties think they'll win back defectors by adopting UKIP's "policies" they've misread the runes. The UKIP phenomenon isn't about policies so much as it's about the disgust with Westminster. Farage's great advantage over the other party leaders is he's the only one of them who can stand in front of a pub going "Ha, ha, ha" without it looking like a photo-op.