Voting Cues and the Incumbency Advantage: a Critical Test1

A possible explanation for the rise of the incumbency advantage in U.S. elections asserts that party and incumbency are close informational substitutes. With the declining psychological importance of party, voters attached themselves to the next available piece of information { incumbency. A critical test of this idea arises in the peculiar circumstances of Minnesota state legislative elections, which were conducted using non-partisan ballots and primaries until 1973. We ̄nd that the introduction of party labels on the ballot and of party primaries increased party voting in Minnesota state senate elections substantially, but, contrary to expectations, the incumbency advantage increased as well. While the increase in partisanship in Minnesota legislative elections runs against the national trends of the time, the increase in incumbency voting resembles trends in Minnesota state elections, Nebraska's non-partisan legislative elections, and state elections throughout the country. The Minnesota test case reveal that party and incumbency are not close substitutes for large numbers of voters, and cue substitution cannot explain the rise of the incumbency advantage. Sometime in the middle of the Twentieth Century, incumbency emerged as a new force in American electoral politics. Political parties had dominated American elections for nearly a century. Although party is still the single best predictor of voter behavior, party attachments declined in the 1950s and 1960s, and incumbency emerged as a substantial additional factor in voters' reasoning and election outcomes. Aldrich and Niemi (1996) go so far as to characterize the last four decades of the century as a new electoral alignment.1 Was the rise of incumbency and the decline of party more than historical coincidence? Some of the earliest and most comprehensive studies of the incumbency advantage argue that the declining importance of party in fact caused the incumbency advantage. In one of the seminal papers on the incumbency advantage, David Mayhew (1974, page 313) writes: \It is possible that incumbents have been pro ̄ting not from any exertions of their own but from changes in voter attitudes. A logic suggests itself. Voters dissatis ̄ed with partisan cues could be searching for any other cues that are available in deciding how to vote. The incumbency cue is readily at hand."2 For their part, the behavior of modern incumbents and challengers may make incumbency an even more salient factor in the minds of voters. Casework, campaign advertising, and other actions of incumbents emphasize their performance in o±ce and often deemphasize party (Cain, Ferejohn, and Fiorina, 1987). While the historical timing seems right, causality is di±cult to determine. Moreover, some ̄ndings cast doubt on the simple cue substitution argument. Ferejohn (1977) shows that party loyalty changed little in U.S. House elections from the 1950s through the 1970s. Krehbiel and Wright (1983, page 140) argue that \dealignment accounts for little of the increase in incumbency voting." Examining U.S. Senate and state gubernatorial elections, 1Gelman and King (1990), Levitt and Wolfram (1997) and others show that the incumbency advantage for members of the U.S. House rose sharply during the 1960s and 1970s. Ansolabehere and Snyder (2002) ̄nd similar patterns for all nearly all statewide o±ces across the United States. 2See also Cover (1977), page 532, and Nelson (1978-89). For more recent arguments along these lines see Kelso (1999) and Iyengar (2002). Kelso writes: \Historically in California, the overwhelming advantage of incumbency has deterred persons from challenging sitting trial court judges. With the support and aid of a political party, however, the incumbency advantage may be su±ciently eroded to encourage increasing numbers of challengers." Iyengar argues: \In the case of non-partisan judicial elections, voters may overcome their lack of information about the candidates experience or professional/legal credentials by relying on name recognition { supporting the candidate whose name is more familiar { or by taking the word of credible public ̄gures who have endorsed particular candidates. In many cases, name recognition may provide incumbent candidates with an edge."