In the wake of mid-decade redistricting and the Supreme Court decision gutting the Voting Rights Act (VRA), there has been a lot of worry about the future of gerrymandering. A common line I’ve heard is that while the partisan effect of the redistricting is not likely to be large, competitive districts are likeliest to be the biggest casualties, which is bad in an already-polarized nation.
I wrote this sentence a few weeks ago, when mid-decade redistricting was mostly a wash. I’m guessing fewer people today would make the claim that gerrymandering’s partisan effect is not likely to be large. Because I can see ahead more than a few days, I had already written in this piece that I was skeptical, that I expect Republicans to benefit at least a little bit, and potentially a lot.
That is still my position in light of everything that has happened since. The basic rationale is that Republicans are more ruthless and less respectful of democratic norms. Democrats are starting to become more ruthless too, but still I expect them to, for instance, be more likely to create maps that abide by the majority-minority district guidelines that the VRA formerly required even after SCOTUS has gutted it. There is already starting to be some basically cope spreading around1 about how Democrats don’t need to violate these former requirements to do more gerrymandering. This is not to mention how Democrats have to dig themselves out of the hole they put themselves in by adopting independent redistricting commissions in many blue states.
The second claim, that gerrymandering is going to lead to fewer competitive districts, is definitely true if sometimes a bit overstated. Sometimes it is in a party’s best interest to gerrymander by creating more competitive seats rather than maximizing the number of safe seats, as Democrats in Oregon have done. If Republicans are generally more willing to gerrymander, then it is probably the right play for the Democrats that are willing to gerrymander to do so by creating more competitive districts in some areas, in order to maximize the number of winnable districts. (They probably largely won’t do that anyway, just cus it’s a little counterintuitive, but they might).
I think most interesting is the core claim, that more competitive seats is better.
The Ideological Effect of Competitive Seats
The primary intuition people have is that more competitive districts is likely to lead to more moderate representatives. If you’re a fan of consensus democracy and think democracy should represent the median view in society better rather than fluctuating between two extremes, as I am, then this is good.
More precisely, usually what we care about is not that there are a lot of moderates elected, but that the median vote in the legislature - the one that determines whether bills pass - is moderate. Note that this logic does not apply the same way when there are supermajority requirements, like the Senate’s 60-vote filibuster, because there you actually also care about how moderate the 40th or 60th senator is. Let’s set that aside for now and just focus on the median vote in the House.
Should we expect more competitive districts to actually lead toward a more moderate median vote? I think it depends.
The general dynamics
The first thing to observe is that competitive districts actually make the results of an election less proportional. If there are 100 seats, 45 safe for each side and 10 swing districts, and a party wins 55% of the vote, they are likely to get exactly 55 seats. If there are 30 swing districts, that party will probably win all 30 and get 65 seats. This extremely disproportionality is an inherent feature of first-past-the-post in single-member-districts, and actually gets worse with more competitive districts.
This is weird and counterintuitive. Many of the people who want moderates elected and hate gerrymandering because of the statement at the top are the same people have actually called for proportional representation to remedy it. Not what you would do if you were concerned about competitive districts!
Bigger majorities because of more competitive districts often lead to a less moderate median representative. As a simple example, suppose 10% of Republicans are moderates, then if Republicans win 51% of the seats you’d expect the median vote to be moderate, while if they win 60% of the seats you wouldn’t.'
In other cases, more competitive districts can lead to a more moderate median representative. Suppose moderates have an electoral edge, then competitive districts will be more likely to elect moderate candidates. This is both because of selection effects - voters select for moderate candidates in the general election - and because of intentional moderation - either representatives strategically moderate to win the general election, or parties are more likely to nominate genuinely moderate representatives in swing districts.
I vibecoded a little applet to understand these dynamics a little better.
More competitive districts leads to a more moderate median representative when there are a lot of moderates in swing districts, and not a ton of very moderate candidates in opposite-party seats:
If there are a lot of moderates in swing districts, but also a decent number of very moderate candidates in opposite-party districts (10+% to opposite party) capable of pulling off upsets - as has generally been the case historically - then this effect disappears or even reverses. This is because reps in opposite-party seats are likely to be the ideological median under extreme gerrymandering.
When there aren’t a ton of moderates in swing districts, but the overall level of moderation is quite high (and varies a lot from representative to representative), then the smaller majorities under extreme gerrymandering lead to a strong effect in the opposite direction:
A priori, I’d think the exact scenario where you get the intuitive effect is somewhat unlikely - when you get to a point where swing-district candidates are moderating a lot, you’d think you’d also see reps in opposite-party safe districts moderating a lot. Notably though, I do think you can make a case that we were in a mild version of this scenario in in 2022 and 24, where Democrats in swing districts substantially outperformed others but without any Democrats winning in deep red districts:
Of course, these are all just toy models, there’s a lot of complexity not captured here, and even here there’s more complexity when you add in asymmetry. (I am pretty confident these are the general dynamics though). Overall, I think it’s hard to predict whether more extreme gerrymandering will lead to a more or less extreme median representative going forward. I suspect the actual effect will be relatively small. And regardless, this is not really why gerrymandering is bad.
Gerrymandering’s primary negative consequence is not its effect on competitive seats
Gerrymandering is bad primarily because it creates a partisan bias, leading to one party taking power even when it loses the popular vote. This is undemocratic.
If the baseline map is slightly uneven, more (naive2) gerrymandering in equal proportion from both sides amplifies the partisan bias substantially. The best way to measure this is by looking at the median partisan lean of the districts, also called the mean-median gap, which is a rough measure of how much each party has to win by in order to get a majority. So a mean-median gap of R+X% means Democrats have to win the popular vote by about X% to win a majority.
This is because if there are many swing districts, a bit of Republican gerrymandering (moving a few swing or blue districts to be solidly Republican) will move the median district from an EVEN district to one of the next middle-most districts, which is maybe like R+1. If there are very few swing districts, then a bit of Republican gerrymandering will move the median district from an EVEN one to the one of the next middle-most districts, which is likely to be far more Republican:
Secondarily, gerrymandering is bad because it nationalizes state-level elections, forcing voters to consider the effect of their vote on their state’s congressional districts, rather than just considering who would do a better job governing. This makes voters less likely to throw out the party that dominates the state even when they do a terrible job governing.
(You might question the extent to which voters actually consider the effects of state-level elections on redistricting. But I do think gerrymandering at least creates a vague feeling that these elections have national consequences, even if voters aren’t making the specific connection in their mind.)
Holding partisan bias constant, gerrymandering’s effect on competitive districts - if a problem at all - comes strictly third.
While it’s true that Democrats can gerrymander a lot more without violating VRA, racial considerations aren’t the only reason Democrats (and Republicans) aren’t maximally ruthless. There are also other constraints like incumbent protections and public opinion/court pressure. If Democrats don’t take advantage of the VRA they’re just going to get out-gerrymandered by Republicans, because Democrats will have to contend with racial considerations and these other constraints, while Republicans will only have to deal with the other constraints.
Nate Silver’s piece doesn’t actually say that Democrats can get away with making VRA-compliant districts, his point is just that even non-VRA-compliant Democratic districts are pretty likely to elect minority representatives. I think he’s basically missing the point - the reason Democrats want to make VRA-compliant districts is not that they elect minority representatives, but because of the brainworm that you are like depriving these minority voters of their political power if you don’t stuff them all in a single district. The other problem with the piece is that you would think it’s about VRA compliance just from reading the title - not good given that most people are unlikely to read the piece!
IE, not if the parties strategically create swing districts like I was describing earlier