Writing for the The Oxford Handbook of Classics in Contemporary Political Theory, political philosophers John Thrasher and Gerald Gaus review Buchanan and Tullock’s The Calculus of Consent:
Calculus advances new methods in an attempt to solve an old problem: the problem of
democratic justification. While democracy claims to be the “rule of the people” in any
actual democratic system we actually find the rule of some people over others. More
formally, the winning coalition in any election is able to impose its authority on the losers.
This is true however large the majority happens to be, and however small the minority is,
unless the vote is unanimous; and even then, there may be an excluded minority of those
who did not or could not vote. Yet at the heart of the democratic ideal is the principle that
all are inherently free and equal, with no natural authority to rule over one another. How
odd then to start from freedom and equality and end with majority coalitions imposing
their policies on minorities merely because they have the numbers to do so. Once we see
this oddity we are confronted with the question: how could the authority of democratic
assemblies over free and equal persons be justified? This is the problem of democratic
justification, a problem that animates Calculus.
…A feature of Calculus typically missed is its optimism. Public choice theory is commonly
characterized as anti-democratic, or as undermining faith in the democratic process
(Barry 1989; Christiano 1996, 2004). Rightly understood though, Calculus is an almost
giddy endorsement of democracy (of a specific form) in the face of what looked like dire
prospects for democratic theory.