A Spatial Model of Voting Fluidity on the United States Supreme Court

Voting fluidity is a common occurrence with its own dynamics during the judicial decision making on the U. S. Supreme Court. This article approaches this issue with a spatial model. Supreme Court justices arc assumed to be rational decision makers pursuing a Court decision that is as close as possible to their ideal points on the ideological continuum. The process of opinion circulation is construed as a bargaining game over the formation of a majority opinion coalition (MOC). Justices interact with each other over the specific contents of the majority opinion until an equilibrium MOC is built. A spatial analysis of all these equilibrium coalitions generates insights into the causes and features of voting fluidity. It also offers a spatial explanation for the empirical observations in past studies