The Gerrymander Effect, Take 2

Earlier today I linked to a post from Eric McGhee suggesting that the post-2010 gerrymandering of the House by Republican legislatures had only a modest effect on this year’s results. You will be unsurprised to learn that I got a lot of pushback on this, which prompted me to go back and check out other research on the subject. Before I got too far, though, I remembered that Sam Wang had done a bunch of work on this, so I went over to his site to see what he came up with.

His methodology is too complicated to try to summarize, but here are his conclusions:

  • Prior to 2010, there was no systematic, nationwide effect from gerrymandering. (See here for more on this.) There was an incumbency effect, in which the majority party has a tendency to keep its majority, but otherwise no net lean in the direction of either Democrats or Republicans when you account for district lines in all 50 states.
  • The 2010 redistricting was more one-sided than in past years.
  • As a result, there’s now a net, systematic, nationwide lean in the direction of the Republican Party. The size of their advantage is calculated as the average vertical distance between the red and black lines in the chart on the right, which turns out to be 6.3 seats.

So the 2010 redistricting really was unusually partisan. But the size of the Republican advantage turns out to be about six seats, very similar to what Eric McGhee came up with. The incumbency effect is about double that, for a total built-in Republican advantage of roughly 20 seats. Accounting for uncertainty, the Republican advantage is 10-30 seats, which is right in line with how much they outperformed the popular vote this year.

I’m interested in further research on this subject, but for now we’ve got two methodologies that produce pretty much the same result. The Republican gerrymander following the 2010 census has given them a permanent tailwind of about six seats, and they’ll keep this for the rest of the decade. Combine that with the incumbency effect, and Democrats are unlikely to regain the majority unless they win about 52 percent of the popular vote.

One More Thing

And it's a big one. Mother Jones is launching a new Corruption Project to do deep, time-intensive reporting on the corruption that is both the cause and result of the crisis in our democracy.

The more we thought about how Mother Jones can have the most impact right now, the more we realized that so many stories come down to corruption: People with wealth and power putting their interests first—and often getting away with it.

Our goal is to understand how we got here and how we might get out. We're aiming to create a reporting position dedicated to uncovering corruption, build a team, and let them investigate for a year—publishing our stories in a concerted window: a special issue of our magazine, video and podcast series, and a dedicated online portal so they don't get lost in the daily deluge of headlines and breaking news.

We want to go all in, and we've got seed funding to get started—but we're looking to raise $500,000 in donations this spring so we can go even bigger. You can read about why we think this project is what the moment demands and what we hope to accomplish—and if you like how it sounds, please help us go big with a tax-deductible donation today.

We Recommend

Latest

Sign up for our newsletters

Subscribe and we'll send Mother Jones straight to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate