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Introducing the 112th Congress
Now that the dust from the 2010 Elections has cleared, it is time to start looking at how the 112th Congress will compare to the 111th. The figure below tracks the ideological positions of the median House member, the mean Democrat, and the mean Republican since 1988. The replacement effect of the 2010 Midterm Elections is unlike anything in recent memory. The shift in the House median is two and a half times what was observed after the 1994 Election, wiping out the effect of Democratic gains in the previous two elections and then some. The 111th was the most liberal Congress in the past three decades; the 112th will be the most conservative.
The 2010 Elections had a profound effect on congressional polarization. Not only will the 112th House be the most polarized on record; 2010 will surpass 1994 as the most polarizing election cycle.
The figure below helps place the historic jump in polarization in perspective. It displays the ideological distributions of House members continuing on from the 111th Congress, alongside the distributions of the entering class of Republicans and the sitting Democrats they defeated. Two features stand out. The first is that the mean entering Republican (1.09) is substantially more conservative than the mean continuing Republican (0.82). In total, 77 percent of freshmen Republicans in the 112th Congress will locate to the right of the party median from the 111th. In other words, nearly 8 in 10 incoming House Republicans would have been on the right wing of the party in the 111th Congress.
The second standout feature is that, contrary to many media accounts, the Republican wave was an equal opportunity un-employer for Democrats. Democrats who lost their reelection bids were slightly more moderate than those who retained their seats—0.61 compared to 0.64—but the difference is statistically insignificant. The attrition rate was greater among centrist Democrats, but there were so few Democrats remaining in the political center that the losses had to come from elsewhere.
The polarization resulting from the 2010 Midterms is fundamentally different and more worrisome than what had preceded it. By historical standards, the post-war era stands out as a period of relatively low partisan polarization. This is largely attributable to the coalition between Northern and Southern Democrats. The increase in polarization during the 103rd through 105th Congress corresponds to the tail end of the Southern partisan realignment, a period during which southern districts that had traditionally elected moderate Democrats (a.k.a. Dixiecrats) began electing conservative Republicans. As the Southern Democrats gradually disappeared throughout the 1980s and 1990s, the parties became more clearly defined, thus returning congressional polarization to the historical norm.
The hollowing out of the political center explained the momentous rise in polarization during the Southern realignment. Now that only a handful of moderates remain in the House, polarization can no longer be portrayed as a story of vanishing moderates. It appears the rise of the extremists has stepped up as the driving force behind congressional polarization.
Campaign Finance Based Forecasts for the 2010 Midterm Elections
As promised, here are my predictions for the 2010 Midterm Elections. The model parts with poll-based forecasting models in predicting that the Democrats will maintain control of the House. It predicts that Democrats will win between 217 and 238 seats, which translates into a loss of 19 to 40 seats. (The complete set of House predictions is available for downloaded as a .csv or a .xls.)
The histogram displays the predicted number of Democratic Seats from 10,000 bootstrap simulations.
If Congress operated more like a Westminster parliamentary system, fixating on which party will win a majority of seats would be more sensible. In such a setting, after assuming power the majority party (or coalition) is free to enact legislation with as little input from the minority as it pleases. This is not the case in Congress. The past two years have been a constant reminder to Democrats that even large electoral majorities do not grant similar levels of legislative control. Current theories of congressional behavior tell us that the position of the median member of Congress can be as important to policy outcomes as which party is in the majority. An advantage of my forecasting model is that it can predict ideological quantities of interest other than seat shares. For example, I can predict the position of the median member in the next Congress and the extent to which partisan polarization will increase or decrease.
The model projects that the position of the median House member in the 112th Congress will be -0.05 with a 95 percent CI between -0.13 and .13. This represents a sizable shift to the right from the median legislator in the 111th Congress, who was located at -0.24. Yet, this will only bring the median back to where it was during the 110th Congress. To place this in perspective, the median House member in the 111th Congress was in the region of Joe Baca (D-CA) and James Oberstar (D-MN). The model predictions place the median member for the 112th Congress in the region of Arthur Davis (D-AL) and James Marshall (D-GA) but could be as far to the right as John McHugh (R-NY) or former Senator Lincoln Chaffee (R-RI), which is still very moderate. According to the model, even in the best-case scenarios, the House median will be much more moderate than what Republicans experienced during the 104th-109th Congress.
The figure below displays the trend lines for the median House member and the means for each party since 1990. Regardless of which party claims a majority after the election, the model projects an increase in partisan polarization. The mean Republican will experience its largest shift to the right ever recorded, while the mean Democrat also will move further to the left as Republican challengers pick off moderate Democratic incumbents. The general rule of thumb for this election is: the larger Republican gains, the greater the increase in polarization.
I report the model predictions faithfully here, but I remain somewhat skeptical of the model predictions for two reasons. The first is that the realm of campaign finance has undergone changes since the previous election cycle. Not accounting for independent expenditures by outside groups might have biased the model in favor of Democrats. On the other hand, the BCRA arguably represented a much larger shock to the campaign finance system than Citizens United, yet the model predictions for the 2004 Elections were right on target. Moreover, the model does not include any variables that relate to campaign expenditures; it only conditions on fundraising patterns, which remain largely unaffected by Citizens United. The second reason is that the model predicted Democrats would win about 10 seats fewer than they actually did in the 2006 Midterm Elections. It is difficult to determine whether this reflects the Mark Foley October surprise or a failure by the model to account for partisan momentum.
I suspect the model predictions are too generous to Democrats by about 8 to 12 seats. Even with the downward adjustment, I still predict the Democrats will retain their majority, but just barely. This is in line with Sandy Gordon’s forecasting model based on calibrated expert raters. Along with Sandy’s forecasts and the recent polls showing that oversampling of landlines can bias polls in favor of Republicans, my model provides additional evidence that poll-based forecasting models are overstating Republican gains. Fortunately, we won’t have to wait long to find out.
A Visual History of Senate Polarization from 1967 to 2010
(Maximize the video and set the quality to 720p HD for best viewing. The video is also available for download from here.)
Each senator is marked by a two-letter state code and is color coded by party membership (Democrat, Republican, Independent). The top grey bar is the distance between the mean Republican and the mean Democrat (the standard measure of partisan polarization). The size of each party’s coalition is displayed at the end of the bars. The lower grey bar is the gridlock interval, which is measured as the distance between the filibuster pivots (the 34th and 66th most conservative senators before the Senate rule change in 1975 and the 41st and 60th thereafter). The ‘M’ imposed on top of the bar marks the position of the median senator.
The ideological estimates are constructed by scaling senate voting records with dynamic optimal classification. Keith Poole’s paper on optimal classification can be found here, and the paper which explains how to extend the method to smooth legislator ideal points over time can be found here.
Ideologically aligned and ideologically divided industries
I have been thinking lately about how the ideological distributions of individual contributors within certain industries might help illuminate the polarized state of U.S. politics. There are two types of distributions that could implicate an industry in abetting polarization. The first distribution is what political scientists would think of as typical of polarization, a bimodal distribution in which individual cluster at each extreme but very few locate in the center. The second is a unimodal distribution located at either extreme. Both distributions are characterized by a preference for extreme candidates over moderates, but the former indicates that members are ideologically divided while the later indicates that most members have similar ideological positions. This distinction is interesting because there is good reason to suspect that the ideologically aligned industries interact with the political system differently than their ideologically divided counterparts.
Industries Aligned with the Left (2008)
Industries Aligned with the Right (2008)
The figures above display the ideological distributions of industries that I refer to as ideologically aligned—that is, composed of members that are ideologically extreme but skew overwhelmingly to the left or right. Living up to frequent accusations by right-wing commentators, the unholy trio of Hollywood, the print media, and academia do indeed appear to be overrun by liberals, with lawyers and online computer services (e.g. Google) not far behind. On the other end of the spectrum, members of the oil and gas, construction, insurance, agricultural and automotive industries are overwhelmingly conservative. Although the ideological orientation of these industries is not much of a surprise, the extent to which these industries favor the extreme, rather than moderate, wings of each party far surpassed my expectations. Some of the distributions more closely resemble what I would expect from occupations that were subject to the spoils system–for instance, US postmasters prior to the Pendleton Act–than major contemporary industries with no official partisan ties.
Granted, ideologically aligned occupations are not the norm. Most industries have enough members on each side of the spectrum to be distinctly bimodal. Some of these industries have distributions that lean heavily in one direction or the other, while others are more balanced. Health care professionals, real estate, investment bankers, and commercial bankers, each at the center of recent political battles over government intervention and reform, are perhaps the best examples of deeply but roughly evenly divided occupations.
Ideologically Divided Industries (2008)
So what might we take away from this? Ansolabehere, De Figueriedo and Snyder (2003) have argued that the increasing proportion of campaign funds raised from individual contributors has helped safeguard our democracy by counteracting the influence of special interests and their PACs. This line of argument help push provisions in the Bipartisan Campaign Reform Act that froze the contribution limits for PACs at $5000 per election, while doubling the contribution limit for individuals to $2000 which was thereafter pegged to inflation.
The existence of ideologically aligned industries brings pause to the notion that money raised from individuals is somehow less corrupting or less influential than money raised from PACs. Insofar as candidates are able to identify those industries vital to their fundraising efforts, why would the incentives to support policy that favors growth in those industries be all that different because the money came from individuals rather than PACs?
Strangely enough, the comprehensive disclosure requirements for individual contributors may have had an effect opposite its intention. Rather than serving primarily to stymie backroom quid pro quid deals, it may have helped solved a coordination problem between legislators and aligned industries, by providing the means for those occupations to signal that enacting policy that favors their industry will fill their preferred party’s campaign coffers while only making a dent in the opposition’s coffers. This may seem less insidious than deals hashed out smoke-filled rooms, but as far as the public is concerned, the effects on policy probably are not all that different.
Ideologically aligned industries might also fan the flames of polarization by encouraging politicians to write-off entire industries as their de-facto opposition. This could manifest itself in mostly harmless ways. For example Senator McCain can get away with dusting off his favorite (and only?) lawyer joke on late night talk shows and stump speeches, while a cash-strapped Democratic presidential hopeful would be better advised to stump against corn subsidies on public health grounds than deride lawyers or other professionals.
Nevertheless, it could also rear its ugly head in policy disputes. Consider the ongoing fight over healthcare. Tort reform is one of the few clear opportunities for bipartisanship. Despite Republicans having oversold tort reform as a solution to keeping health care down costs, such reform would have at least had a marginal effect on costs and would have made the health reform bill much more attractive to the medical industry. (One recent survey found 92 percent of doctors in favor of malpractice reform, while 85 percent reported that the threat of malpractice lawsuits has prevented them from practicing medicine properly—it was commissioned by Jackson Health Care Services, so I would take the results with a grain of salt. A more direct estimate of the potential savings from health care tort reform can be found in the NYT’s Economix blog.) Yet Democratic lawmakers have continually dismissed tort reform with the flimsy explanation that medical malpractice is not a big deal because it only constitutes about 2-3 percent of medical costs. This is despite the notion that tort reform seems to be a natural complement to the White House’s early proposals to eliminate waste by freeing doctors to perform tests only when they deem them medically necessary rather resorting to “defensive medicine” to minimize legal liability.
One question to ponder is whether ideologically aligned industries have contributed more to the pattern of polarization than ideologically divided industries. My initial thought on the matter is that ideologically aligned industries have help blaze a path for congressional polarization by supporting extreme candidates while other industries merely responded to the increasingly polarized candidate pool. Once I have a scaling that includes a time-trend of all election cycles going back to 1980, it should be possible to track how the ideological distributions industries have changed over time and examine whether some industries acted as a catalyst to polarization while others merely adjusted to it.
Polarization in the Senate: How much is a lack of manners to blame?
There has been much talk as of late about what has caused politics in this country to become so polarized. The political science literature usually points to changes in procedural rules, regional sorting, a rise in economic inequality, extremism of party activists, and to a lesser extent, redistricting to explain the rise in polarization. However, the word on the street seems to be that Congress polarized because members from opposing parties no longer invite each other over to dinner. At least that is what Evan Bayh—the soon to be former senator from Indiana, who is also a son of a senator with the uncommon experience of taking up their fathers’ profession—had to say about it in an op-ed published in the NYT on Sunday. We political scientists tend to chalk up this account as something akin to pop-psychology, but given the level of genuine animosity apparent in Congress it is hard to see how it has not taken a toll, even if we lack sound methods to measure it.
One way to get a rough gauge of how the decline in bipartisan manners may have contributed to polarization is to look at how periods marked by bitter partisan disputes affected voting behavior of the parties. In order to get a measure of this, I use estimates from a roll call scaling method described here that uses kernel methods to smooth legislator trends over time. This makes it possible to track how polarization changes from one day to the next, in contrast to DW-NOMINATE, the only widely used estimation technique that allows for inter-temporal movement of ideal points, which only recovers a single estimate for each two-year Congress.
The figure above shows that day-by-day polarization trend closely tracks the corresponding DW-NOMINATE trend. Both trends tell a similar story in the long run: polarization reaches a low-point around the 90th Senate (1967-1968) and steadily increases in the following decades. At the same time, the day-by-day trend reveals that political polarization varies considerably between elections.
The next figure magnifies the polarization trend for the period between the 103rd and 109th Senates so that it is possible to view how Senate polarization responds to political events. There are three notable events that affect the polarization trend. The first event occurs during the 104th Congress and corresponds perfectly with the federal government shutdowns that resulted after the Republican controlled Congress failed to pass a budget bill. The second event is Senator Jeffords’ decision to switch parties during the 107th Senate, which was followed by a sharp decline in polarization. The third notable event is the rapid rise in polarization during the run up to and through the early months of the Iraq War. In December 2003, this trend abruptly ceases and then falls, corresponding with the capture of Saddam Hussein.
Some of the events seem to have lasting influence. This is best exemplified by the jump in polarization corresponding with the 1995 government shutdown. Rather than observing a spike in polarization that quickly returns to its previous level, the trend remains at its heightened level, perhaps, as Senator Bayh has suggested, as a result of increased animosity that weakened bipartisan goodwill.
Interestingly, despite my initial expectation that Clinton impeachment trial had increased polarization, in his op-ed Senator Bayh points to the impeachment trial as the one of the two instances (the other being September 11th) where all senators gathered for something other than purely ceremonial occasions and as a highlight of bipartisanship during his twelve years in the Senate:
All of us gathered in the Old Senate Chamber. For several hours we debated how to proceed. Finally, Ted Kennedy and Phil Gramm, ideological opposites, were given the task of forging a compromise. They did, and it was unanimously ratified.
This might offer some context as to why the polarization trend is in decline during that period. It also paints the somewhat paradoxical picture where a Senator best known for his consistently liberal voting record was also one of the most potent de-polarizing forces in the Senate. Although there is no way to know, something tells me that had Ted Kennedy not passed away last summer there would be much less talk at the moment about reforming the filibuster.
Ideological Cartography 