Party polarization is endogenous

Centrist wonks lament party polarization, but rarely point out that it’s not something that just happened. In the context of heterogeneous political geography and malleable district boundaries, a two-party system doesn’t yield the centrism it is often credited with, but a superficial and artificial polarization that demands an eventual populist response. Party polarization is the endogenous and predictable result of incentives created by a first-past-the-post voting system susceptible to gerrymandering.

For gerrymandering to work, the voting behavior of citizens must be identifiable and stable. The way gerrymandering works is to decrease the number of votes that are “wasted” in safe localities by redistricting a party’s voters into less safe or marginally unfavorable localities where they might tilt the balance. The expected outcome is more, closer, wins for the gerrymandering party. However, those closer wins are necessarily more fragile. Even small shifts in party identification or voting behavior, any deviation from the roles assigned to each of us by the gerrymanderers, can undo all their good work. Worse still, deviations are rarely idiosyncratic to a single district. Gerrymandering leaves a party more vulnerable to systematic deviations, which make “wave elections”. Thus gerrymandering creates incentives for incumbents and party operatives to try to cement party identification in stone. Candidates in both parties emphasize issues on which their members are unusually unified and the other party’s members are unusually opposed over issues that might be more important to their constituents, but less clearly drawn across party lines. They then work very hard to make positions on these issues, and only these issues, tribal markers, essential to voters’ identities. We end up in a world with extreme polarization of party platform and identification, despite not so much actual polarization among voters when a broader spectrum of issues than those emphasized by the parties is considered.

A puzzle in this account is why the party disadvantaged on net by gerrymandering should play along. The answer to this is simple. Both parties gerrymander when they get to draw the lines, although the Republicans gerrymandered unusually aggressively and with unusual success in 2010. Further, even absent gerrymandering, both parties “naturally” have districts where they have some advantage, but where elections remain close and competitive. The safest strategy for an incumbent member of Congress in a closely divided district is to cement in place the coalition that brung her the last time, rather than roll the dice on poaching her opponent’s voters (which may open up her own voters to poaching). Incumbent members of Congress in both parties tend to prefer a stably polarized electorate to one in which common ground increases the uncertainty surrounding voter behavior. Even when this disadvantages the national party, in the social science cliché, it’s a case of concentrated benefits and widely dispersed costs. Post 2010, nationally, the Democrats might have been better off de-emphasizing party-polarized issues and embracing causes with cross-party popular appeal. But neither members of Congress individually, nor party activists who’ve made their careers and raised their funds as fighters across well-worn political battle lines, would assent to that strategy. Further, issues with broad popular appeal that have been neglected by both political parties are often issues to which both parties’ “donor classes” are allergic.


20 Responses to “Party polarization is endogenous”

  1. vlade writes:

    Which is why I said that in the UK, if the voters really wanted to show it to the elites, they missed the bus with the LibDem referendum on proportional representation. Of course with heavy opposition from both Tories and Labour.

  2. timm0 writes:

    The issue of “going along” with the gerrymandering is a fascinating one that should be explored further. In Pennsylvania, the most senior Congress Critter in the Democratic Party is Mr. Brady. His district is in Philadelphia, where political corruption and bullying are an intrinsic sport for Dem wannabes. He was effectively in charge of the Dem side of the “negotiations” with the Republican governor and state legislature.

    Reportedly, the eastern side of the state, where Dems hold a significant advantage, was thrown under the bus immediately in order to save his district. The proposed lines were agreed to by the Dem side at least twice because at least 2 redistricting plans were appealed to high courts. Brady’s district was preserved in all proposed versions. Even now, if you look at the district lines, it’s utterly laughable. A state with a majority of registered Democrats sends 13 Republicans and 5 Dems to the House.

    However, it would be wrong to blame it solely on evil Republicans – evil Republicans found some equally evil, self-absorbed toads on the other side of the aisle to play like a fiddle. The Reps had a long, team view while the Dems obediently followed the one that served the loudest, most powerful toad at the pond. The Clinton presidential campaign fiasco is just a super-sized version of the same problem: the Clintons made themselves the mafia kingpins of the Party (and gateway to all big-money pockets), used it to lock down all the super delegates… all the while ignoring the big picture, which showed – even during the primaries – that she was the weakest projected performer against trump in the general election. The results all along are Dem candidates at large lose while 1% of top Dems get rich in many ways.

  3. Nick Bradley writes:

    But Democrats *do* campaign on broadly popular policies, such as a higher minimum wage and gun control.

    However, republicans are the white party now, and it doesn’t really matter what they advocate. See: Trump, Donald.

    I think that there may very well be a D wave in 2018, with a lot of disgusted moderate republicans getting on board. But to do that, democrats need a broad narrative – something more than “Trump is mean”

  4. Peter writes:

    What’s the most *politically feasible* way for this system to be disrupted? A third party or independent President? Or maybe a swing bloc of a few centrist independent Senators who refuse to caucus with either party? (Thereby giving up a lot of power/leverage but maybe gaining even more if they can stick together.) Or what?

  5. “Party polarization” is based on a two dimensional Newtonian model of how politics works. It’s the wrong metaphor and yields wrong answers. The result is the word “populist” which as used in the language means “a politician who falsifies the political spectrum model of politics by combining colors not imagined to be next to each other.”

    It’s a map/geography problem which exactly parallels the Newtonian/Cartesian bullshit which economics uses to map a Darwinian world of human behavior. It’s not an accident. Political science and economics are the two remaining fields of Enlightenment science which retain Newtonian metaphors to understand human behavior.

  6. stone writes:

    vlade@1, I thought the UK tragedy was that the LibDems gave us a referendum not on genuine proportional representation but on a Single-Transferable-Vote system. IMO if we had a proportional representation system (such as our UK system for voting for MEPs), then that would stop the policy zig-zagging where each government spends a term undoing what has just been done. It would also prevent “safe” constituencies being taken for granted and their needs abandoned.
    A Single-Transferable-Vote system addresses none of that. It only addresses the issue of voters not voting for their first choice because they fear that might be a wasted vote – not surprisingly that was what the LibDems were most concerned about.

  7. stone writes:

    I’m really not so sure that the blame can be laid at Gerrymandering. The UK doesn’t have the same issue with Gerrymandering as you have in the USA, but we have the same issue of first-past-the-post elections and a resultant abandonment of the political concerns of a large swathe of constituents. We have consequently seen UKIP aiming to grow in traditionally safe Labour seats. In the UK our “Boundary Commission” is expressly supposed to prevent Gerymanndering :-“Boundary changes can have a significant effect on the results of elections,[6] but boundary commissions do not take any account of voting patterns in their deliberations, or consider what the effect of their recommendations on the outcome of an election may be”

  8. reason writes:

    Thornton Hall
    I find your post very interesting, but don’t fully understand what you are trying to say. Could you expand it a bit.

  9. reason writes:

    A question to Steve here – it is not just gerrymandering that is relevant, consider for comparison the Australian system
    1. Compulsory voting
    2. Single transferable vote
    3. (Independent electoral commission responsible for boundaries – so no gerrymandering).

  10. reason writes:

    It strikes me also (re his last point and the disadvantages party) – isn’t the big issue in the US that the boundaries are made by State governments and that the parties have different strengths in different states. If it was done at national level for instance – the incentives would be completely different, and the disadvantaged party would probably get rid of the system when(if) they gain power.

  11. reason writes:

    I’m not so sure that the Republicans really are the “white” party (it is more the other way around – the Democrats are the minorities party). What the Republicans seem to be to me are a coalition of the mean and the unthinking (making Trump a unity candidate). Bush represented the unthinking wing, and Romney the mean wing.

  12. stone writes:

    Reason@11, to me the Republicans (and our UK Tories) seek the ideal of personal responsibility. I have a lot of respect and sympathy with that. I campaign against them but to me it is a question of balance and trade offs rather than them being “mean and unthinking”.

  13. reason writes:

    No they don’t, or they wouldn’t just lie all the time (and they would be much more careful about deregulating – regulation – i.e. holding companies responsible).

  14. reason writes:

    P.S. There may at some stage have been people in those parties who genuinely were interested in promoting personal responsibility, but now it is just a clearly transparent front for selfishness (on the one hand) and a retreat from rationality (on the other).

  15. Lord writes:

    I think appealing to the mythical centrist may be irrelevant and that elections are really won or lost on base turnout.

  16. Detroit Dan writes:

    Lord@15– Your note on base turnout accords well with Steve’s message. Base turnout may depend upon issues which are not highly polarized. Thus, Trump’s base turned out much more to vote on trade and his passion for American workers.

    reason@13– You make a good point about accountability.

    SRW– Thanks as always for the intelligent and constructive post.

    Getting back to the polarization issue, it is a global phenomenon, with, for example, Corbyn and Hamon demonstrating leftist strength in Britain and France. Not to mention Beppe Grillo in Italy. On the other side you have Putin in Russia and Duterte in the Philippines. Populism is the single underlying factor. To put it in crasser terms, it’s the economy, stupid.

    Capitalism makes the economy paramount, so it’s not surprising that our neo-liberal, capitalist global consensus is churning in favor of popular demand for ever increasing economic strength. The right wants to deliver by removing all impediments to national prosperity, despite the obvious need for many of the impediments (fairness, environmental protection, compassion, maintain peace). The socialists want to derail the train whose momentum is heading to the competitive abyss.

    Ezra Klein and other centrists hand-wringers seem to see where the train is headed, but remain frozen like deer in the headlights. In my opinion, we all should join with Sanders, Corbyn, Hamon, the Pope, and other socialists and deal with pressing human, and populist, human needs.

  17. Andrew Curry writes:

    @vlade: The British referendum wasn’t for proportional representation, but for the single alternative vote, which in some cases would actually produce worse outcomes than first past the post. So it was hard to mobilise around. I voted for AV in the referendum, but only because I thought it might weaken the attachment of the British political system to First Past The Post. The main reason it lost was because Clegg was out-manoevered by the Tories: he got them to agree to the referendum without them also making a commitment that they would support a ‘Yes’ vote. Cameron and Osborne must have been laughing all the way down Downing Street.

  18. reason writes:

    Andrew Curry @17
    “Worse outcomes” – there you go missing the whole point of democracy. Democracy is not about outcomes – it is about process. And the whole point of AV is not necessarily about breaking the two party system, it is about changing political dynamics to make the parties more responsive to public opinion. Look at what has happened in Australian with the frequent intraparty regicide if you want to see how the dynamics are affected.

  19. Foppe writes:

    Steve: Back in Republican Rome, it was considered dangerous to allow others to push through legislation that might lead you to lose voters (that’s why the Gracchi brothers were murdered). There doesn’t quite seem to be a modern analogous case. but I do wonder why the Dems have never enacted legislation to guarantee the right to abortion access, other than because it’s just so damned handy to always have that hanging over people’s heads, and to suck up attention.
    In any case, while I don’t disagree that this is a relevant factor, I would emphasize that another, large part of the reason is that these “strongly divided” issues dominate the way they do because too much of what politics should be about is bipartisanly considered to be taboo — i.e., those policy issues the addressing of which that would deliver concrete material benefits to all, rather than, say, only those making <$140k/y, would cost money. And fiscal conservatives — conservatives + the professional class — hate that, unless the recipients "deserve" said money. Additionally, because most legislation is reactive, it often is short-sighted. In <the New Jim Crow, Michelle Alexander lists a number of cases in which it is obvious — at the very least “in hindsight” — that envy was built-in, and broad-based support lacking. This lesson, however, seems to be a hard one, probably in part because there is a tendency towards tinkering over radical redesign, and because politicians have “lost contact with the soil”, and spend way too much of their time poring over and improving text, and way too little talking to real people about the consequences of new legislation, and about related problems by slightly less “deserving” people who might feel left out, etc., and what can be done to make their lives better.

  20. derrida derider writes:

    “Party polarization is the endogenous and predictable result of incentives created by a first-past-the-post voting system susceptible to gerrymandering.”

    It’s not only, or even mainly, gerrymandering. Having candidates chosen by primaries voted on only by party adherents – who almost by definition are more extreme than the median voter – is going to do it (that’s why you have the familiar pattern of candidates making extreme statements in their primary campaign then trying to disown them in the general). Voluntary voting also means intensity of preferences matter, which pushes things towards extremes.

    And of course first-past-the-post means it remains a two party system where product differentiation between the parties is essential. Compared to FPTP single transferable vote (STV) in single member electorates demonstrably favours centrist third parties, who can win seats without a plurality of first preferences by picking up transferred votes (preferences in the Australian jargon) from both sides. Think of it as like the voters striking for a compromise candidate in a deadlocked leadership ballot. That’s why the Lib-Dems wanted it – that they displayed great political incompetence as to means doesn’t mean their goal wasn’t the correct one for them.

    Proportional representation (PR) favours fourth, fifth, sixth, seventh, etc parties which tend to extremes.