How Dangerous are the Supporters of Small Parties

The leaflet sent to me by the No to AV Campaign protests that AV would allow the supporters of small parties to decide the results of elections.

That claim is not supported by any analysis of election results, or by any other evidence. I suspect it is based on an assumption that all or nearly all the supporters of a minority party might give their second preferences to the less popular of the two most popular parties, thus enabling that party’s candidate to win. I doubt that assumption.

References to the BNP suggest there is an assumption that the supporters of some small parties are not the sort of people who should be allowed to decide election results. Yet how can they be prevented from doing so ? Any with a strong preference for one of the larger parties rather than the another could exercise that preference and so help to decide the result under the First Past the Post system. They just need to ignore their own party’s candidate and vote for the candidate of whichever of the larger parties they find least objectionable. In the many constituencies where a particular small party has no candidate, its supporters either vote for someone else, or don't vote at all. If they vote for some else, they might influence the election result.

Perhaps some of the ‘no’ folk hanker after some way of disenfranchising those whose opinions they consider unsound.