Forecasting the Senate vote on the Supreme Court vacancy

Abstract

This paper forecasts current senators’ votes on Merrick Garland’s nomination to the U.S. Supreme Court, in the unlikely case that a vote actually takes place. The forecasts are necessarily conditional, awaiting measurement of the nominee’s characteristics. Nonetheless, a model that combines parameters estimated from existing data with values of some measurable characteristics of senators—particularly their party affiliations, party loyalty levels, and ideological positions—is sufficient to identify potential swing voters in the Senate. By accounting for a more nuanced and refined understanding of the confirmation process, our model reveals that if President Obama were to nominate almost any nominee (conservative or liberal) today, that nominee would be rejected if a vote was allowed to take place. So why nominate anyone at all? Obama’s hope for a successful confirmation must come from the stochastic component, that is, from outside the traditional decision-making calculus.