What Redistricting Means For Sunlight’s APIs


With the election 4 months away we’re starting to get questions about when our various APIs and projects that depend upon them will return the newly redistricted legislative boundaries.

Gerrymandering political cartoon

The short answer is that we will most likely not be able to support new district boundaries until after the November 2012 election (but before they technically go into effect for the purposes of representation in 2013).

If you’re interested in the reasoning behind this decision, read on, but be warned, redistricting is a lot more complex than “the state has released new boundaries, let’s load them.”

Which Boundary Is Right?

This sentiment is one of the most common ones: “the state has finished redistricting, you still return the old ones, please update them.” This isn’t the correct option given the fact that most uses of the district boundary data deal with returning information on who represents a given district, and that won’t change until January of 2013[1] (or later in some state legislatures) when those elected in November of this year take their seats. Until then, citizens continue to be a part of the district they were in as of the last election.

So given that it isn’t correct to simply replace the current boundaries, ideally we’d be able to support both old and new boundaries in the interim. We were in fact hoping to have support for the redistricted boundaries by this summer so that people hoping to use them for election-related purposes would be able to pass a parameter into the API indicating that they wanted the 2013 districts. Typically for this geospatial data we rely on the Census’ aggregation of various political boundaries, but for the new boundaries they have an estimated release date of Spring 2013 which would mean several months of us returning old districts, even after they took full effect.

Plan B: 50 Disparate Sources

While trying to decide how to proceed after the disappointing news from the Census team we were informed about the Statistical Reform in Redistricting Project. They’ve done a great job of collecting states’ proposed boundaries as part of their work to analyze the fairness of legislative districts. While they’ve done the first, cruicial step by collecting all of the redistricting information in one place, the files still differ enough to make importing them into a unified system like our API a cumbersome and error-prone task.

Despite these difficulties, we do plan to import the various state boundaries instead of waiting for the Census to come around. The downside is that we will have to sacrifice our initial goal of providing the shapefiles before the election. There are approximately 150 shapefiles to be processed (50 states, each with two state-level and one federal level shapefile). Additionally, quite a few states are still awaiting the outcome of a court case or Department of Justice approval (see Justin Levitt’s guide to redistricting for details on the current legal status of redistricting plans). Given the unexpected additional effort involved in loading the new boundaries, we will need to wait until the legal situation surrounding the remaining plans has been settled to avoid repeating this work multiple times.

We’ll continue to work towards the goal of providing the 2013 shapefiles as soon as we can be confident in their quality, but given the current situation we wanted to provide this update on why it’ll take longer than everyone had hoped. Of course, there’s always a possibility that things will change and we’ll find the time or find an easier path to this goal. We’ll be sure to update both here and on the Sunlight Labs Google Group when we have more to share.

[1]: States with odd-year election cycles (New Jersey, Virginia, and Louisiana) do have their new state districts in effect and the Open States API now returns the current boundaries for those states.