Party System Development and Democratic Stability in Nigeria’s Fourth Republic

This study analyses the development of Nigeria's party system since the return to civilian rule in 1999, examining the structural characteristics of the system including party institutionalisation, ideological differentiation, fragmentation, and volatility, and assessing their implications for democratic stability. A well-institutionalised party system is widely regarded as a prerequisite for stable democratic governance, providing organisational structures for political competition and meaningful representation of citizen interests. Using a comparative historical analysis design, the study draws on electoral data from all presidential and governorship elections between 1999 and 2023, party registration and de-registration records from the Independent National Electoral Commission, and secondary literature on party system development in emerging democracies. The party system institutionalisation theory developed in the comparative politics literature is applied to evaluate Nigerian parties against international benchmarks. Findings reveal that Nigeria's party system has undergone significant structural transformation over its four electoral cycles, moving from a dominant party system under the Peoples Democratic Party to a more competitive but volatile system marked by frequent party formation, merger, and defection. Ideological differentiation between parties remains weak, with policy differences rarely explaining inter-party competition. Electoral volatility, measured by aggregate vote share shifts between elections, is high by international standards, indicating a shallow attachment of voters to parties as stable political organisations. Recommendations include electoral reforms that reduce the incentive for party multiplication, internal party democracy requirements, and civic education emphasising party platform rather than personal loyalty. Keywords: party system, democratic stability, Fourth Republic, party institutionalisation, Nigeria