Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Jones, David R. 2010. Partisan Polarization and Congressional Accountability in House Elections. American Journal of Political Science 54 (April): 323-337.
Shortly before the 2008 Congressional elections, only 36% believed that most members of Congress deserved reelection. These numbers were not unusual. Since consistent polling began in the 1970s, Congressional approval has rarely been higher than 40%. Nevertheless, 94% of U.S. House members won reelection.
For years, political scientists have explained this seeming paradox by pointing out that members of Congress can win reelection by running against Congress. A representative can urge his voters to send him back time after time so that he can keep working to fix the broken system. As Fenno wrote in Home Style, "It is easy for each Congressman to explain to his own supporters why he cannot be blamed for the performance of the collectivity . . . because the internal diversity and decentralization of the institution provide such a wide variety of collegial villains to flay before one's supporters at home" (1978, 167).
In his textbook on Congressional elections, Gary Jacobson sums up the dominant view among political scientists: "Members are not held individually responsible for their collective performance in governing." (2004, 227).
David Jones has a recent article in AJPS that challenges this long held view. Jones looks back 60 years to a report commissioned in 1950 by the American Political Science Association Toward a More Responsive Two-Party System. That report urged "greater party cohesion in Congress," suggesting that the presence of liberal Republicans and conservative Democrats makes it more difficult for individual voters to hold their representative accountable for Congress's collective activities.
Jones argues that the APSA report was correct: If the two parties become more distinct (i.e. polarized), then it should be easier for voters to blame members of the majority party for Congress's collectively bad (or good) performance. And, as it happens, there's been quite a bit of research in recent years showing that Congress has, in fact, become more polarized.
If Jones is right, then we're in a new era. It may have been true 20, 30, or 40 years ago that members of Congress could evade accountability for Congress's overall activities, but rising polarization has enabled voters to punish or reward Representatives for Congress's collective performance.
To test this possibility, Jones compiled each incumbent Representative's electoral margin going back decades, producing thousands of data points. He then regressed those vote margins on a variety of independent variables. Among others, he regressed vote margins on Congress's overall approval ratings. More importantly, he also interacted those approval ratings with measures of polarization (party unity).
Take a look at Figure 1 from Jones's article (below). Along the X axis, Jones shows each year back through 1976. Along the Y axis, he shows that estimated effect of overall Congressional approval on individual incumbents' vote margins for that year. By the end of the series, the estimated effect of overall approval rises above 0.50 (for members of the majority party). In other words, a one percentage point drop in Congressional approval (perhaps from 40 to 39) leads us to expect a 0.50+ drop in each incumbent's vote margin. This is a powerful effect, subject to a powerful interaction.
It's worth noting that there is not similar interaction for members of the minority. Back in the days of low polarization, minority members could win reelection by running against Congress, just like members of the majority. Rising polarization has not prevented minority party members from continuing to run against Congress--and why should it? Minority party members can continue to win by running against Congress, citing all the majority's misdeeds. Nothing has changed for the minority.
This is an interesting and worthwhile article. It leaves me wondering, though, why 90+% of incumbents continue to win reelection. I began this review by pointing out a seeming paradox from 2008--not from 1976. Even in the most recent Congressional elections, 36% of voters said that most members did not deserve reelection, yet 94% of members won reelection. More generally, we continue to observe Congress (overall) receiving markedly low approval while individual members receive very high approval from their constituents.
If Jones is correct, then we ought not to observe this pattern so strongly anymore, yet we do. I'm not sure how to respond to Jones's analysis given this continuing disconnect between overall and individual Congressional approval. Perhaps Jones has a serious problem in his statistical analysis that I'm not seeing resulting in an inflated estimate of the interaction. Or perhaps Congressional elections are sufficiently different from Congressional approval that this paradox can persist in approval data even as it evaporates in election results. I'm at a loss to resolve this puzzle.
Research on similar subjects
Jones, David R. (author) • American Journal of Political Science • American Politics • Blame • Congressional Elections • Incumbency Advantage • Parties • Party Government • Polarization • Responsiveness • Voting