Party Competition, Nomination Errors, and the Electoral Decline of the Japan Socialist Party

Social democratic parties have thrived in most democracies, but the Japan Socialist Party (JSP) has declined to such an extent that it has become almost electorally irrelevant. Explanations for this involve such factors as the party's ideological rigidity and poor leadership, which have kept it from responding effectively to the increased electoral competition it has faced. While such explanations are generally accurate, this essay shows that there is more to the story of the JSP's electoral decline, by investigating the socialists' decline in Japan at the election district level from 1958 through 1993. This is where the JSP's endorsed candidates won and lost district seats; our investigation shows that, during this period, the JSP faced increased electoral competition on its left and right flanks, which hurt it electorally in both direct and indirect ways. It hurt the JSP directly by inhibiting the ability of the party's candidates to win legislative seats in district elections, and indirectly by leading the party to commit too many nomination errors, which, in turn, led to the loss of district seats that it otherwise would have obtained. Overall, the study's results suggest that, while the JSP could not have stopped its electoral decline completely, it could have preserved more of its support if it had been able to bridge its internal ideological gaps to keep itself from fragmenting.