ABSTRACT
In the study of party bans and democratic responses to extremism, ‘militant democracy’ is a paradigmatic concept. However, many scholars have criticized the concept for being too vague, imprecise or narrowly focused on legal instruments. Following from such critiques, this chapter presents a new approach to the study of variation in democratic states’ responses to anti-system parties. Drawing on existing empirical studies and results of a ‘critical’ case study on the illegalization of Herri Batasuna and its successors in 2003, the chapter develops five hypotheses for explaining why some democracies ban parties but others do not. The hypotheses are: Democracies ban anti-system parties if these parties have been ‘securitized’ as an existential threat; if veto players prefer proscription; if anti-system parties do not unambiguously reject violence; if alternative forms of marginalization are not effective; and if partisan party-ban-veto-players do not need to cooperate with targeted anti-system parties to win and maintain office or achieve policy goals. Focusing on party ban, legalization and failed ban cases in Spain, Britain and Germany permits an examination of cases expected to replicate findings of existing studies (literal replication) or that predict contrasting results but for reasons predicted by existing studies (theoretical replication).
