RESEARCH NOTE Evaluating the Impact of Vice Presidential Selection on Voter Choice BERNARD GROFMAN AND REUBEN KLINE University of California, Irvine We update and extend work by Wattenberg and Grofman (1993) and Wattenberg (1995) on the consequences of vice presidential selection for voter choice in U.S. presidential elections by offering a simple quantitative model that allows us to measure both potential and actual effects of differences between vice presidential and presidential preferences. We model the impact of vice presidential selection as a weighted average of the differences in voting behavior between those with differing combinations of presidential and vice presidential preferences and the size of the pool of voters who exhibit such preferences. One holder of the office of vice president, John Nance Garner (1868-1967), reput- edly said that “[t]he vice-presidency ain’t worth a pitcher of warm piss.” 1 However, as one heartbeat away from the presidency, in the modern “red phone” era, the importance of the vice president has generally been thought to have grown. And, certainly in 2008, there was almost as much hullabaloo about the Republican vice presidential pick as there was about John McCain himself, with a long period of time in which media and blogosphere coverage of Sarah Palin was at a fever pitch. There have been only a few attempts to determine the effect of vice presidential selection on presidential vote totals (see Adkison 1982; Romero 2001; Wattenberg 1995; 1. This quote is often bowdlerized, with “spit” used as a euphemism for urinary product. Bernard Grofman is Jack W. Peltason Chair in the Department of Political Science at the University of California, Irvine, and director of the Center for the Study of Democracy. His most recent book is Behavioral Social Choice, coauthored with Michael Regenwetter, Michael, A. A. J. Marley, and Ilia Tsetlin. Reuben Kline is a doctoral candidate in the Department of Political Science and a graduate fellow in the Center for the Study of Democracy at the University of California, Irvine. AUTHORS’ NOTE: We are indebted to the ICPSR for NES data. The first-named author’s participation in this research was partially supported under Social Sciences and Humanities Research Council of Canada Grant #410-2007- 2153, to study “Political Competition” (co–principal investigators: Stanley Winer and J. Stephen Ferris); the second- named author’s participation was supported by funding from the Jack W. Peltason (Bren Foundation) Endowed Chair, University of California, Irvine. We also wish to acknowledge our debt to Sue Ludeman for bibliographic assistance. Presidential Studies Quarterly 40, no. 2 (June) 303 © 2010 Center for the Study of the Presidency