ABSTRACT
Studies on measures democracies employ to marginalize anti-system parties suggest the politics of government formation may affect decisions to ban political parties. More specifically, democracies may be less likely to ban parties if (1) use of the cordon sanitaire – or exclusion of an anti-system party from office or legislative alliances – provides an effective alternative to party banning and (2) if mainstream parties are likely to benefit from cooperation with an anti-system party in government or legislative alliances. In this chapter, I examine these hypotheses in relation to party bans in Spain, the United Kingdom and Germany. Incentives to cooperate with anti-system parties are estimated using anti-system parties’ Penrose-Banzaf scores, positioning of median legislators and involvement in theoretical ‘minimum winning coalitions’ or ‘minimal connected winning coalitions’. The chapter shows that effective marginalization of anti-system parties through a policy of cordon sanitaire and incentives to cooperate with anti-system parties did not vary systematically across cases where parties were banned, legalized or where attempts to ban them failed. This suggests that availability of effective alternatives to party ban such as cordon sanitaire and incentives for mainstream parties to cooperate with, rather than ban, anti-system parties are not important explanations for party ban decisions.
