Dominant party systems present two major puzzles. If dominant party advantages are overwhelming, then why do opposition parties form at all? On the other hand, if opposition parties compete in genuine elections, then why does single-party dominance persist? Despite the predictions of existing theory, 16 countries on four continents had dominant parties during the 20th century and, by century's end, 11 had transformed into fully competitive democracies with turnover.

This book offered a theory to explain both equilibrium dominance and its breakdown; that is, a theory to account for both stable long-term single-party dominance and the incumbent party's eventual loss at the polls. I argued that hyper-incumbency advantages deeply affect partisan competition and help sustain dominance. In particular, dominant parties' monopoly or near monopoly access to public resources allows them to outspend challengers at every turn, saturate the media, pay armies of canvassers, blanket the national territory with their logo, and generally speak to voters through a megaphone while opposition parties speak with a whisper. Most importantly, dominant parties' hyper-incumbency advantages allow them to bribe voters with patronage goods. Dominant parties also raise the costs of participating in the opposition by imposing opportunity costs for not joining the incumbent and, in some systems, by targeting repression against opposition forces when patronage fails.

Identifying that dominant parties use resources and sometimes use repression to sustain their rule is not particularly surprising or innovative; however, prior research has been largely descriptive and has not incorporated these elements into a complete theory of single-party dominance.