This book examines the causal impact of ideology through a comparative-historical analysis of three cases of 'post-imperial democracy': the early Third Republic in France (1870-1886); the Weimar Republic in Germany (1918-1934); and post-Soviet Russia (1992-2008). Hanson argues that political ideologies are typically necessary for the mobilization of enduring, independent national party organizations in uncertain democracies. By presenting an explicit and desirable picture of the political future, successful ideologues induce individuals to embrace a long-run strategy of cooperation with other converts. When enough new converts cooperate in this way, it enables sustained collective action to defend and extend party power. Successful party ideologies thus have the character of self-fulfilling prophecies: by portraying the future polity as one organized to serve the interests of those loyal to specific ideological principles, they help to bring political organizations centered on these principles into being.
This is a highly ambitious and largely compelling synthesis of modern social/political theory and comparative historical analysis. Its major theoretical contribution is to show how ideology can help solve the daunting collective action problems involved in party formation and organization by extending the time horizons of adherents. In other words, it consciously builds on Weber's theoretical framework to specify a clear mechanism for the causal impact of ideas in politics and history. Hanson sums up his key claim as "no ideologies, no parties"—or, to put it more precisely, no strong parties.