Interesting stuff, right down the bottom of this article, about the impact of third party candidates on people’s voting intentions.
The conventional wisdom is that where there’s a third party candidate they usually “steal” votes from the candidate they’re perceived as being closest to, but apparently that’s not the case.
Lowenthal offers some explanations for this counterintuitive finding. She says it could have to do with the popularity effect — what Cialdini describes as social proof — where people who don’t know where their priorities are look to others to tell them what to do. Because two politicians are pushing for the same issue — in this case, more new business — voters assume it must be more important than they originally thought.
I’m not sure how well this theory would translate into British politics – perhaps the arguement could be made that Nick Clegg’s decision to move the Lib Dems closer to the Tories is part of what’s helping Cameron in the polls.
But it seems to me there are also other currents at work in politics which impact on voting intentions; policy positions, media portrayal, circumstances, and the money parties spend on getting their messages across to mention a few.