Rethinking dominant party systems

Empiricist definitions of ‘dominant party systems’ incorporating ‘longitudinal’ time requirements risk tautology and create unacceptable lags in recognizing dominance. We urgently need an analytic definition that can identify parties as dominant independently from their tenure of office. I suggest that a party can be recognized as dominant if three criteria are met simultaneously: - The party is seen as exceptionally effective by voters, so that it is set apart from all other parties. - It consequently has an extensive ‘core’ or protected area of the ideological space, within which no other party can compete effectively for voters’ support. - At the basic minimum level of effectiveness that voters use to judge whether to participate or not, the lead party has a wider potential appeal to more voters than its rivals This approach means that we can identify a party as dominant immediately it establishes a higher level of effectiveness. It also generates some key hypotheses that are well supported in the existing literature on dominant party systems and could be more precisely tested in future, specifically: - Factionalism should be a more serious problem for dominant party leaders than in more competitive systems. - In ‘uncrowded’ ideological space one-party dominance will be sustained by the strong logic of opposition parties adopting ‘clear water’ positional strategies. - Only when some opposition parties adopt ‘convergent’ or ‘deeply convergent’ positioning strategies will support for dominant parties tend to be seriously eroded. - Factional exits from the dominant party are the most likely route by which opposition parties with ‘deeply convergent’ strategies emerge. - Greater crowding of the ideological space is a key stimulus to some opposition parties adopting convergent or deeply convergent strategies. It also helps overcome the positional advantages that dominant parties often have, making minimum connected winning coalitions easier for opposition parties. - Hence the multiplication of parties is a key dynamic undermining dominant party systems