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How important is gerrymandering? and How to most effectively use one’s political energy?

Andy Stein writes:

I think a lot of people (me included) would be interested to read an updated blog post from you on gerrymandering, even if your conclusions haven’t changed at all from your 2009 blog post [see also here]. Lots of people are talking about it now and Obama seems like he’ll be working on it this year and there’s a Tufts summer school course where they’re training quantitative PhDs to be expert witnesses. Initially, I thought it would be fun to attend, but as best I can tell from the limited reading I’ve done, it doesn’t seem like gerrymandering itself has that big of an effect. It seems to be that because Democrats like cities, even compact districts favor Republicans.

I’d also be curious to read a post from you on the most effective ways to use one’s polical energy for something productive. The thing I’m trying to learn more about now is how I can help work on improving our criminal justice system on the state level, since state politics seem more manageable and less tribal than national politics.

Here’s what I wrote in 2009:

Declining competitiveness in U.S. House elections cannot be explained by gerrymandering. I’m not saying that “gerrymandering” is a good thing—I’d prefer bipartisan redistricting or some sort of impartial system—but the data do not support the idea that redistricting is some sort of incumbent protection plan or exacerbator of partisan division.

In addition, political scientists have frequently noted that Democrats and Republicans have become increasingly polarized in the Senate as well as in the House, even though Senate seats are not redistricted.

And here’s how Alan Abramowitz, Brad Alexander, and Matthew Gunning put it:

The increasing correlation among district partisanship, incumbency, and campaign spending means that the effects of these three variables tend to reinforce each other to a greater extent than in the past. The result is a pattern of reinforcing advantages that leads to extraordinarily uncompetitive elections.

I added:

I’m not saying that gerrymandering is always benign; there are certainly some places where it has been used to make districts with unnecessarily high partisan concentrations. But, in aggregate, that’s not what has happened, at least according to our research.

But that was then, etc., so it’s reasonable for Stein to ask what’s happened in the eight years since. The short answer is that I’ve not studied the problem. I’ve read some newspaper articles suggesting that a few states have major gerrymanders in the Republican party’s favor, but that’s no substitute for a systematic analysis along the lines of our 1994 paper. My guess (again, without looking at the data) is that gerrymandering in some states is currently giving a few seats to the Republicans in the House of Representatives but that it does not explain the larger pattern of polarization in Congress that we’ve seen in the past few years with party-line or near-party-line votes on health care policy, confirmations for cabinet nominees, etc.

That said, the redistricting system in the United States is inherently partisan, so it’s probably a good idea for activists to get involved on both sides so that the fight in every state is balanced.

Regarding your other question, on effective ways to use one’s polical energy for something productive: I have no idea. Working on particular legislative battles can have some effect, also direct personal contact is supposed to make a difference: I guess that can involve directly talking with voters or political activists, or getting involved in activities and organizations that involve people talking with each other about politics. The other big thing is legislative primary election campaigns. It think that most primary elections are not seriously contested, and primaries can sometimes seem like a sideshow—but powerful incumbent politicians typically started off their careers by winning primary elections. So your primary campaign today could determine the political leaders of the future. And there’s also the indirect effect of influencing incumbent legislators who don’t want to lose in the primary.

All this counsel could apply to activists anywhere on the political spectrum. That said, I’d like to think of this as positive-sum advice in that (a) I hope that if activists on both sides are involved in redistricting, this will help keep the entire system fair, and (b) my advice regarding political participation should, if applied to both sides, keep politicians more responsive to the voters, which I think would be a net gain, even when some of these voters hold positions with which I disagree.


  1. RJB says:

    On the question of productive political energy, it really matters whether you are trying to make something happen or stop it from happening. You can search for “Indivisible: A Practical Guide for Resisting the Trump Agenda” to see some arguments that it is a lot easier to resist, because the message is so simple (“No!”) and you just have to repeat it loud and long with a lot of people together. Forging a path to yes on something requires compromise, and allies will have plenty of room for disagreement.

    My impression (based more on business than politics) is that positive change typically requires a lot of behind the scenes work, so money and other forms of indirect support are very valuable to let the insiders do their job.

  2. Robert Kubinec says:

    So what then is the institutional mechanism that helps Republican totals in the House/state legislatures far exceed popular vote shares, considering that these bodies should reflect proportionality to some extent.

    Is it a) split-ticket voting or b) an artifact of first-past-the-post districts that each elect a single representative?

    • Andrew says:


      A lot of this is the geographic concentration of Democratic votes, especially in recent years, so that Democrats are winning in districts where they’re getting 80% of the vote, while Republicans are winning in districts where they get 60% of the vote. This sort of imbalance can be created by gerrymandering, but it can also happen just from geography. So, yes, it’s an artifact of first-past-the-post districts.

    • Andrew says:


      I went to the linked paper, which begins, “What is the effect of gerrymandering on the partisan outcomes of United States Congressional elections? A major challenge to answering this question is in determining the outcomes that would have resulted in the absence of gerrymandering. Since we only observe Congressional elections where the districts have potentially been gerrymandered, we lack a non-gerrymandered counterfactual that would allow us to isolate its true effect.”

      I understand their general point, but it’s not quite correct to say “we lack a non-gerrymandered counterfactual.” Gerrymandering is not done in all states. Some states have bipartisan redistricting plans. Or, at least, this used to be the case. I’d also be careful about referring to the “true effect” of gerrymandering, as the effect hast to vary a lot based on political and geographic conditions in the state.

      Similarly, I have problems with other statements in the paper, such as, “If the actual outcome and the simulated outcome are the same, then it can be said that the districts produce a result that is no different from a result that would have been produced had the districts been drawn without partisan intent.” The simulated outcome is under one particular model, which is not necessarily anything like “would have been produced had the districts been drawn without partisan intent.”

      On the plus side, I think the paper is clear, its graphs are excellent, and I agree with their general point that most of the partisan bias we see in the seats-votes curve is coming from geography rather than gerrymandering. I wouldn’t take too seriously their claim that, in the absence of gerrymandering, the Republicans would have only one fewer seat in Congress—I think the effect could be a bit bigger than that—but I agree that the effect of gerrymandering on the partisan balance is in Congress is small.

      • Ian Fellows says:

        I don’t study this in depth, but I did write a blog post looking into gerrymandering after the 2012 election that looks into that “counterfactual” ( ). I found a lot to suggest a strong gerrymandering effect. It seems to me that if geographic voter distribution is the driver, then it would have to be more of a factor in states with partisan controlled redistricting than in non-partisan states. Is there any evidence of this?

        • Jonathan (another one) says:

          Ian: I’m not sure what you’re saying here. Why should geographic voter distribution be more of a factor in states with partisan-controlled redistricting?

          • Ian Fellows says:

            Yes, sorry for not being clear. If one were to attempt to explain the data that I saw in 2012 with the “democrats tend to clump” hypothesis, it would have to be the case that democrats clump more in states with republican redistricting control than in non-partisan redistricted states.

  3. David says:

    I worked at a state party for three years and primaries can easily be both not seriously contested and a mess even if they are seriously contested. I’ve seen it from state house races all the way up to governor. So there’s definitely potential in primaries. It’s difficult with very limited resources. But it could be the best bang for your buck.

    As for increased partisanship, would main mover or starter of that be realignment after civil rights? That it more neatly coalesced different ideologies into the two parties? At the local level that seemed to take longer than at the presidential and national level, which I assume is because of incumbency effect. And from there it’s been a nationalization of local politics and a GOP much less willing to compromise that explains the continued partisanship. Is that the basic story?

    • Dzhaughn says:

      “So there’s definitely potential in primaries.” Yeah, like in Oregon. Circa 1980, the idea of a Republican included Tom McCall (who annexed the entire coastline to stop development,) a thoroughgoing dove like Mark Hatfield, and a moderate like Bob Packwood.

      Anti-abortion groups, in the subsequent few decades, worked very hard and were very successful in influencing the Republican primaries, gradually starting about 1984 until today. By now, Oregon Democrats don’t even need to bother with gerrymandering.

      So how effective was this action? Totally successful and utterly self-defeating, at the same time.

  4. Jacob says:

    Re: political activism and voting issues in particular, I’d plug FairVote ( They’re working to advance ranked-choice (aka instant runoff) voting, which should lead to more responsive elections. They also advocate combining districts into multi-person elections, so say combine 5 districts and have each election select 5 candidates

  5. Michael says:

    With your new post I’m wondering if you stand by your work on JudgeIt as a tool. I understand Gary has updated his method in last year’s Arizona redistricting SCOTUS case. Can we expect an update to JudgeIt?

  6. Eric says:

    Andrew, a naive question: If gerrymandering does not make elections less competitive (i.e., safer for incumbents), why is it practiced?

    • Andrew says:


      Redistricting is required in the U.S. every 10 years. So if you’re going to redistrict, it makes sense to try your best to gerrymander—to bias things in your party’s favor. If there were no constraints, gerrymandering could indeed make elections less competitive. But there are constraints. In no particular order:

      1. Most legislative elections are already noncompetitive, so even if gerrymandering makes them slightly less competitive, you’ll hardly notice.

      2. There’s a tension between the goal of getting individual safe seats (winning elections by huge margins) and helping your party (winning elections by narrow margins so that you’re not wasting votes).

      3. There are legal constraints: too much of a gerrymander and it can be thrown out by the courts.

      4. There are numerical constraints: you need the same number of people in each districts.

      5. There are political constraints in states where there is not one-party control.

      6. Political conditions change over time. A good gerrymander for 2012 might not be so effective by the time 2018 comes along.

      • Eric says:

        I always assumed gerrymandering “works”. I guess what surprised me most was #1. The risk of 3 and 6 seems high if gerrymandering is not effective.

        I live in NC US District 1 (1 of the top 10 most gerrymandered districts ( Gerrymandering seems to be an art form in NC (pun intended).

        • Andrew says:


          There’s no doubt that gerrymandering is real, and that it has real effects in particular states at particular times. I don’t think the aggregate effect is large in favor of either party, but it’s not nothing.

          P.S. I heard that the gerrymandering in North Carolina is much worse than in North Korea!

          • Jonathan (another one) says:

            In Charlie’s link above, North Carolina is indeed a Republican outlier and the biggest proportional outlier, by about 1 mean seat, but California is about a 2 seat gain for the Democrats. (Of course, California is much larger, so proportionately it’s about the same.) Even odder is that the next highest Democratic-biased district (about .75 seats) is a Republican-controlled state: Arizona.

            • chris parker says:


              If I’m not mistaken, Arizona isn’t a gerrymander state inasmuch as its lines are drawn by a non-partisan citizen board. Case went to the Supreme Court. Perhaps there is an over-aggregating going on that doesn’t account for state differences in ability to gerrymander.

        • Martha (Smith) says:

          A couple of days ago I came across a more recent Washington post article on gerrymandering:

          It uses a measure called “the efficiency gap”. I’d be interested to hear what others think of this measure and the court ruling based on using it.

          (Austin, where I live, has been heavily gerrymandered for quite some time — sometimes my congressional district has stretched to the Rio Grande Valley, sometimes to Houston suburbs, sometimes to Dallas suburbs, sometimes to West Texas.)

          • John Mashey says:

            If I recall correctly, Austin manged to be split among 6 districts, 5 GOP and 1 DEM. Is that still true?

            • Martha (Smith) says:

              I find it hard to keep track. I think there are indeed currently six districts that include parts of Austin. (See the map at and enlarge the small map that’s just to the left of the panhandle.) I’m not sure, but I think the only one that is majority democratic is 35.

              (BTW, when I talked about “my” congressional district, I meant that the district that my house is located in changed, not that I moved. Sometimes the change meant I was in a different district, sometimes it meant that the boundaries of the district changed to include different parts of Texas)

              • Christopher Peterson says:

                That’s correct. Lloyd Doggett is the only Democratic Rep; his district is mostly in Austin and San Antonio, with a very small connecting segment.

              • John Mashey says:

                Thanks, I noticed a while ago that Lamar Smith(TX-21) has 2 snakey arms to take parts of San Antonio & Austin into a reliable GOP district.

      • Jonathan (another one) says:

        One other feature is bipartisan gerrymandering to maintain minority representation. Georgia is a good example of this. It is Republican-controlled, but there are strong pressures to keep minority representation (partly, these are the legal constraints of 3, but not completely). So the creation of minority-majority districts automatically makes the Republican districts even more Republican, such that, on net, Georgia actually has less Republican representation than their numbers would suggest, but in a way that keeps Republican seats very safe.

      • Dzhaughn says:

        There are lots of ways gerrymandering can be effective without changing the distribution of the legislature. One might imagine it leads to cheaper or more predictable campaigns, more stable career paths for politicians, clearer choices for successors when someone is promoted to statewide office. And it might be good for a politician to have extremists from the other party getting elected elsewhere.

  7. Z says:

    Andrew, I think you should write a Slate piece on this. This was extremely surprising to me. All the left-leaning, intelligent, numerate politics writers I read put a lot of emphasis on gerrymandering. I suppose most of their points continue to hold if ‘gerrymandering’ is replaced by ‘unfavorable geographic distribution’, but still.

    • Andrew says:


      Every bit matters, so it makes sense for political activists to work on gerrymandering. But there’s probably more potential electoral gain from altering the political message to appeal to a more geographically dispersed groups of voters.

  8. Jonathan says:

    I had the best comment ever but I’m sick and deleted it by mistake! So here is the shorter, crappier version:

    1. Arguments about the fundamental shape of democracy recur: the power of concentration over the less concentrated and vice versa. Electoral College. That cities make more of GDP. The “real America”. The Federalist Papers.

    2. People don’t realize each district include over 700,000 people. This means a district would be either an entire city or much of one and part of the metro area. Cut it up some and you still have concentration related to the sheer size of 700k per. Look at NC: you have a couple districts which are pretty much just Charlotte or Raleigh.

    3. These arguments reflect underlying polarity. We know abortion is one but I think Democrats are largely unaware of the meaning of or the roots of the other. Talking to friends who are somewhat gleeful about the poor Trump start, I said the worst start was Bill Clinton’s and no one even thinks about it though it reverberates loudly today. That is, in March, 1993, after only a few months in office, he approved the assault on the Branch Davidians in Waco, TX. The US government killed something like 75 US citizens, including 25 children, firing heavy weapons on their building and then battering into it as it caught fire and burned them to death. This was only months after Ruby Ridge (just before the election), when the US government may have attacked a militia family without announcing they were the government and then undeniably a sharpshooter shot the mother in the head while she was holding her 10 month old. Until Waco, only the militia and white rights nutcases believed the government was even a potential enemy. While one can argue this was part of a progression from distrust of government programs through Reagan’s 9 scariest words, this moment quickly became a mainstream fear that manifested as a much more absolutist stance about gun rights. The NRA shifted. People started to argue citizens have a right to arm themselves against a potentially oppressive government, which is one reason why they “resist” impositions on so-called “assault weapons”: they see the government trying to disarm a populace that must be vigilant against exactly what the government is doing. If that fear seems irrational, explain the vast spate of articles of the past weeks which exploit and foster fear. This kind of fear brings out – in both cases – absurdities: claims the Jews were disarmed by Hitler, Windsor Canada schools afraid to cross into Detroit, regular immigration raids portrayed as new measures, the rosy-eyed view that Obama only deported “criminals” (which if thought through would mean those here illegally are actually all criminals because he deported about 2.7 million of them!). It beggars my mind that the Democrats could not understand this. Hillary Clinton, even putting aside her “clinging to guns” words, represents this fear and the party put out on campaign as her main “surrogate” the actual guy who did this (and who also locked up vast numbers of black Americans)! This speaks to lack of party self-awareness, sort of like the way Paul Krugman et al can talk about the small percentage of jobs lost to trade deals without recognizing that these are each persons due at least the same level of sympathy as a visa holder wanting to study in the US. But that’s not the way we think: people are statistics except when our politics say they’re people or they’re people except when our politics say they’re statistics.

  9. Democrat focusing on gerrymandering is like making a horrible investment, and then spending your time reoptimizing your transaction costs, since it would have prevented you from losing 2 basis points of your massive loss.

    • mpledger says:

      But it matters for two reasons:
      1) next time two basis points might be important – Mr Micawber’s idea of happiness etc; and
      2) fairness matters because without democracy withers and dies.

    • poorlando says:

      Great comment. If the left wants to waste its energy on gerrymandering, I’m all for it, as it diverts the left’s energy and attention from trying to implement their truly horrible policies.

      • Andrew says:


        Setting aside “the left” or “the right,” you can be sure that both Democrats and Republicans will continue to pursue gerrymandering, as they have for centuries. But they don’t see it as a waste of energy; rather, they gerrymander (and work to block gerrymanders on the other side) as a way to increase their representation in the legislature, thus facilitating the implementation of their policies, horrible and otherwise.

        In short, political energy is not a fixed quantity. Parties and activists work on gerrymandering, not as an alternative to implementing policies, but as a means to being able to implement the policies that they want.

  10. Rahul says:

    Naive question: What does “declining competitiveness” mean in the context of an election?

    Does it mean an election is less closely contested? Or….?

  11. John Mashey says:

    I haven’t looked closely at the data, but the combination of less-partisan gerrymandering and top-two primaries may yield some useful effects.
    Specifically, natural geography may well make some district winnable only by GOP or Dem, but the top-two primary can support same-party challengers to incumbents, and maybe candidates more centrist than get through normal primaries. at least, that’s the hypothesis. We’ll see.

    • poorlando says:

      “maybe candidates more centrist than get through normal primaries. at least, that’s the hypothesis. We’ll see.”

      In California, as a result of top two, the choice was between two Democrats for US Senate. I thought I saw some exit poll showing that Republicans simply declined to vote in that race. So the notion that Republicans would inject some moderation into the result by voting for what a Republican would view as the lesser of two evils might not have panned out the way theory suggests. California Republicans weren’t able to hold their nose in order to give voice to their preference.

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