The first comprehensive account of how the justices of the U.S. Supreme Court achieve consensus. "The heart of The Puzzle of Unanimity is an empirical study of all the unanimous and near-unanimous decisions the Supreme Court issued between 1953 and 2004 . . . And for those readers who come to this book believing that the justices arrive at consensus primarily because of determinate law or ideological convergence or strategic considerations or some other overriding causal factor, this book offers a powerful challenge to these kinds of reductionist assumptions."