[Here is the second of three guest posts by David Schleicher.–RH]
It wasn’t hard to predict the big stories of the 2010 election. For instance, given the state of the economy and the uncommonly large majorities racked up by Democrats in 2008, it is unsurprising that this is a rough year for Democrats, or that a large number of Democrats elected in swing districts in 2006 and 2008 are at risk of losing their seats.
One story, however, is surprising: the extent to which the parties differ on the big issues of the day. Ordinarily, following Anthony Downs, we might assume that parties would make moderate policy offerings, chasing the ever-elusive median voter. Nothing of the sort has happened this year, particularly as Republican primary voters chose the more conservative candidate (or scared the moderate out of the party) in no fewer than 9 Senate races this year. Sometimes the media is right: The story of the year is almost definitely Christine O’Donnell, Sharon Angle, Alan Grayson and the absence of median voter politics.
Judged by ordinary metrics, the degree of polarization in Congress and the electorate has rising for decades — the number of ticket splitters and swing voters in the electorate and the amount of agreement among Members of Congress from different parties has been falling for about 30 or so years now. While political scientists have spent the last twenty or so years debating the causes of polarization, legal scholars have not done too much with this trend. (Rick Pildes is a notable and important exception; his must-read new piece, Why The Center Does Not Hold explains the important role played by the Voting Rights Act in creating our modern polarized two-party system and much else as well — make sure to check it out.) To the extent polarization gets discussed by legal scholars, it is usually used as a boogeyman, a fate to be avoided and an argument for voting reform, like the adoption of instant run-off voting or open or top-two primaries.
The national discussion of polarization could use a better understanding of the role of election law, or more specifically how legal institutions translate voter preferences into party positions. The story of our growing polarization is at least in part a story about election law, but it is not necessarily an unattractive one (at least it does not necessarily make our election laws seem unattractive.) But to see this we need to look at American politics in comparative perspective.
Over the last decade or two, the rest of the democratic world, including virtually every other country that like the United States has first-past-the-post (FPTP) or plurality wins) vote counting, has seen the development of new parties or substantial success for existing smaller parties, including radical ones. Party polarization — here meaning not just parties that are distinct from one another but parties that promote policies that are distant from one another — is likely the American version of the whatever worldwide phenomenon produced new and successful third (and fourth) parties in other countries.
The reason we see polarization in the United State instead of the development of new parties is our election law system, particularly the availability and openness of our primary elections. When some portion of the population develops preferences well outside the current mainstream defined by the two major parties — like this year’s Tea Party movement — the availability of primary elections provides these voters and activists with the option of contesting for the leadership of one of the two mainstream political parties, rather than starting out on their own.
Primaries thus allow for polarization rather than party system fracture, and are probably the reason for the continued survival of the U.S.’s two-party system in the face of widely divergent popular opinion.
If we take FPTP vote counting as a given, having polarization rather than fracture produces substantial benefits; it provides clearer choices for voters and there are no wasted votes. Further, having only two parties inside a FPTP system preserves the crucial role in American election for the median voter: determining who wins each general election. As a result, we can expect a polarized two-party system to produce policy that follows median voter preferences in the long run. However, polarization means that there will be a high degree of variance, as each election will produce a winner who does not promote median-voter preferred policies. However, in the face of an electorate (or at least the engaged part of the electorate) with very widely divergent preferences, party fracture or party polarization may be the only choices.

When we use the term polarization, we combine two different ideas: distinctness, or the lack of overlap between Democratic positions and Republican positions, and distance, or how different the positions of the parties are on the key issues of the day. Distinctness is quite attractive to most people — if all Republicans are more conservative than all Democrats, it makes it easier for poorly informed voters to vote in line with their preferences. But distance is more problematic, as it suggests that elections will not result in policies that reflect the preferences of the median voter. When people worry about polarization, I think this is what they are really after, the idea that Republicans and Democrats are just so right/left that mainstream preferences get ignored. Though the Tea Party has made the fringe element in American politics more visible this year, polarization is a long-term, and much bemoaned, trend.
But in a two-party system, even if there is distance between the parties — very right-wing Republicans and very left-wing Democrats — the expected value of policies, or the average result across elections, –will still likely equal the preferences of the median voter. If the party closer to the mainstream wins, the long run average of results will equal to the preferences of the median voter. However, if there is polarization, there will be a high variance around that long run average, as neither party is, by assumption, moderate. Polarization will result in more radical policies in any given period, but will not change the prediction that the long-run average of the result of elections will be moderate.
Remembering this point will let us see benefits (and true costs) of the American electoral system. One problem with most discussions of American politics is their parochialism, as if many of the things that effect American politics are only felt inside our borders. Over the past decade or so, throughout the world, party systems have fractured. For instance, in a number of proportional representation countries, we have seen the rise of radical parties on both the right-nationalist (e.g. the Sweden Democrats) and left (e.g. Die Linke in Germany). What is notable about many of these parties is that they are often radical enough that other parties — even those that are theoretically on the same side of the political spectrum — won’t form coalitions with them, leading to minority governments, weird coalitions, or grand coalitions between right and left wing parties.
But this phenomenon is not limited to European proportional representation systems. “Westminster Systems” like Britain have single-member districts and first-past-the-post (FPTP) vote counting, just like our Congress, and hence are supposed to have only two parties, a rule so strict political scientists call it Duverger’s Law. (The logic of the Law is pretty simple — neither people nor candidates and activists like their efforts to be wasted and so crowd to the two most viable candidates or parties). But the major Westminster systems — Britain, Canada, Australia and India — all have multiple party systems and now minority governments. The United States stands virtually alone among major countries in the stability of its two party system.
Why other countries are seeing such a rise in non-mainstream parties is unclear. But one way to understand American polarization is that the rise in distance between the parties is a function of whatever it is that is causing the rise in third parties around the world.
When movements develop that are oppositional to the major parties — e.g. because their preferences are well-outside the mainstream — they face a choice between trying to challenge the entrenched order or sucking it up and supporting the party they find least objectionable. Virtually no country other than the United States has significantly open primaries, where party members can choose candidates for all types of offices. When oppositional movements develop in other countries, the possibility of substantially influencing (or taking over) one of the major parties is pretty limited — the parties have entrenched insiders and bureaucracies that stop that kind of thing. While most will follow the predictions of Duverger’s Law nonetheless and suck it up, some will care little about which of the lesser-of-two-evils wins and run on their own, particularly if they have little reason to believe that one of the two major parties will move in their direction.
In the United States, the exact opposite is true. Because joining American parties is relatively easy, primaries make it relatively easy for an outside group to influence the major parties. As a result, primaries reduce the cost of staying inside the two-party system.
This year provides a perfect example of this. The Tea Party is pretty clearly oppositional to both Democrats and mainstream Republicans, as one can see in all of the Tea Party inspired Republican primary challenges this year. (Notably, Democratic incumbents did just fine this cycle — the “anti-incumbent” sentiment was a Republican-only trend.) Rather than set out on their own, as they might have in another country, Tea Party activists decided to influence who was chosen as Republican candidates.
This phenomenon can happen among moderates opposed to the mainstream parties, as you can see if you compare the Social Democrats who bolted from the Labour Party in Britain in the 1980s and the Democratic Leadership Council, which took over large swathes of the Democratic Party in the late 80s and early 90s. But more often than not, groups that oppose both major parties enough to think about bolting from them will form on the fringes of politics. If they attempt to influence the major parties, they will have the effect of moving a major party away from median voter preferences.
So, if similar outsider groups develop in these two types of systems, we would expect third parties more often in systems without primaries, and greater distance between the parties in systems that have them. American polarization, in this understanding, is just how our electoral system swallows the same shock(s) to the system of voter preferences that produced third parties in other electoral systems.
This makes polarization look rather more attractive than goo-goos would generally have it, although not without costs. The existence of third parties inside a FPTP system creates problems. Because FPTP voting systems result in the loss of votes for third place candidates, they bias the results of elections. Votes for Nader didn’t affect the result in 2000, nor for that matter, will votes for Republican Dan Maes in Colorado this year. As a result, it can be unclear in a three candidate race which of the two major candidates is the most preferred by the electorate. Duverger’s Law is normative, and not merely positive.
This means that election results not necessarily — even in the long run — result in policies that match median voter preferences. In countries with both FPTP elections and more than two parties, we do not discover which party is preferred by a majority of voters. And, because parties receive seats that are not proportional to their vote totals, the way they would be in a PR system, there is no reason to believe that the coalitions formed among parties are going to be representative either. There is simply no reason to believe that in any given election or over time that a FPTP system with multiple parties will produce results that are responsive to voter preferences. Also, having only two parties makes it more likely that voters will choose the candidates and parties they actually prefer, as it reduces the difficulty of figuring out who to support for poorly informed voters. If there is widely divergent popular opinion in the electorate, having it expressed in three parties (rather than two polarized ones) is likely to produce policies that are not equal to what the median voter would choose.
However, polarization will increase the variance of policy results. This too is costly, but should be blunted by the American constitutional system, which preserves roles — the Senate, the Courts — for the parties that won elections in the near past. But having rapid (and repeated) changes in public policy can create important costs that should not be underrated.
There is obviously much more to say about party polarization. But whatever is said, we should think hard about how our election system converts our preferences into party positions. And no matter how tempting it is to imagine ourselves to be unique, or how hard it is to imagine a European Glenn Beck or Keith Olberman, we should be careful when we assume that what is happening in American politics is actually an American-only phenomenon. More likely, we just haven’t yet done the work of translation.