This book provides a nice history of the evolution of voting rules, with emphasis on supermajority rules, but is less successful in its attempt to argue that supermajority rule should presumptively be replaced with majority rule. Schwartzberg simultaneously argues that majority rule is superior to supermajority rule because the latter creates a bias in favor of the status quo, and acknowledges that a status quo bias is justified so that people can plan their lives. Her solution–what she calls “complex majoritarianism”–is the manipulation of majority rules so that they are applied to favor–the status quo. For example, she favors constitutional amendment requiring a temporally separated majority vote in the legislature (plus subsequent ratification), but the effect is just bias in favor of the status quo except in the unlikely event that preferences don’t change. She argues that this approach advances deliberation but deliberation can be encouraged in other ways and in any event the status quo bias is not resolved.
The book is right to emphasize historical, empirical, and institutional factors as opposed to the sometimes tiresome analytics of social choice theory–as emphasized by this enthusiastic review here–but Schwartzberg’s argument against supermajority is ultimately analytic itself, based on abstract considerations of human dignity, rather than grounded in history or empiricism. The empirical fact that the book doesn’t come to terms with is that supermajority rule is well-nigh universal, not only in constitutions but virtually every organization–clubs, corporations, civic associations, nonprofits–where people voluntarily come together and use supermajority rules to enhance stability and to prevent situational majorities from expropriating from minorities.