Explaining the (Non)Occurrence of Equal Divisions on the U.S. Supreme Court

Abstract

When the U.S. Supreme Court sits with an even number of justices participating, there is a risk that the Court will be deadlocked in a tied vote. While this outcome awards the individual respondent with a victory, it also preserves circuit splits and other ambiguities in the law. In this article, we examine the conditions under which an even-membered Supreme Court actually results in a tie vote. We argue that the Court recognizes the potentially damaging consequences of 4-4 rulings and seeks to avoid them when those consequences would be most severe. Consistent with that conjecture, we find that ties are less likely when a decision is necessary to resolve a dispute in the lower courts and when cases are important to the executive branch.