How established parties reduce other parties’ electoral support: the strategy of parroting the pariah

In every democracy, established political parties are challenged by other parties. Established parties react in various ways to other parties’ presence. A key hypothesis in the relevant literature is that established parties can decrease another party’s electoral support by parroting it, i.e. adopting its core policy issue position. This article argues, and demonstrates empirically, that this hypothesised effect mainly occurs in the event that a critical prerequisite is in place. Parroting a party decreases its support only if that party is ostracised at the same time. The article classifies a party as ostracised if its largest established competitor systematically rules out all political cooperation with it. Analysing 296 election results of 28 West European parties (1944–2011), evidence is found for a parrot effect – however, concerning ostracised parties only. On several occasions established parties have substantially decreased another party’s support by simultaneously parroting that party and ostracising it.