The Journal of Politics


Optimal Supermajority Requirements in a Two-Party System

Michael Peressa1

a1 University of Rochester


Legislative governance in the United States is characterized by a system of checks and balances. On the one hand, agenda-setting power is concentrated. The majority party has significant control over the agenda. Such power is tempered by supermajority requirements (such as the 60-vote requirement for invoking cloture), bicameralism, and the presidential veto. I develop a theory of legislative outcomes which incorporates supermajority requirements. I argue that supermajority requirements can, in fact, serve an important purpose in balancing concentrated agenda-setting power. I find that substantial supermajority requirements are optimal for legislation, if the aim is to enact policies preferred by the median voter.

(Received May 09 2008)

(Accepted November 25 2008)


Michael Peress is assistant professor of political science, University of Rochester, Rochester, NY 14627.