The Incumbency Advantage in the US Congress: A Roller-Coaster Relationship

Abstract

While every student in American politics knows that the incumbency advantage grew post‐1965, it is less clear as to whether or not this growth has been sustainable throughout the 1980s, 1990s and 2000s. Focusing on the last three decades, we show that the electoral margins of sitting members of the House of Representatives have not linearly grown over the past 60 years. On the contrary, the constant increase in incumbents' vote shares between the 1960s and 1980s could not be sustained in the 1990s. In fact, in the 1990s, the incumbency advantage dropped sharply to levels experienced in the 1960s. In recent years, the electoral margin of sitting House members seems to have grown again to levels comparable to those in the 1970s.

What Are Good‐Looking Candidates, and Can They Sway Election Results?*

“…The unanswered question remains whether this predicted “beauty premium” has any meaning in terms of actual electoral victory. In an environment where most incumbents win reelection and do so with large margins (Cox and Katz, ; Gelman and King, ; Stockemer and Praino, ), it does seem unlikely that the relatively small attractiveness effect our model shows could actually determine electoral results.…”

American Exceptionalism Revisited

“…As a result, the vote gap is now back at the same level as in the 1970s. So instead of a steady increase, which for long was the expected trend, the curve over the decades can rather be described as a roller-coaster pattern-with fairly modest shifts up and down (Stockmer and Praino 2012).…”

“…Nevertheless, he was alluding to a widely recognized phenomenon: that making one's way into Congress-and especially the lower chamber-was a steep uphill battle indeed. By this time (in the 1980s), the probability that a challenger would be able to oust an incumbent Representative was less than 10 percent (Stockmer and Praino 2012;Smith 2013).…”

“…The focus in House elections is generally local, but it sometimes happens that a broad swing in party preferences among the public leaves its mark, resulting in an unusually high number of defeated incumbents. The 1994 and 2010 elections are examples of such "wave elections," strongly dominated by national, party-related issues (Highton 2011;Stockmer and Praino 2012).…”

“…11 Regarding the other aspect of the advantage of incumbency-the difference in voting shares between the contenders-it would come as no surprise by now that the gap between the candidates is higher in elections where a sitting member of the House takes part than it is in open-seat elections (where no incumbent is standing). From the 1950s up into the first decade of the new century, the difference in voting share between the two forms of elections has generally been 5 to 10 percentage points (Stockmer and Praino 2012).…”