Although I wasn’t thrilled to see the Supreme Court kick the can down the road, the Roberts decision and the Kagan concurrence are quite clarifying, logically speaking. These justices have, in some ways, sorted things out nicely.

The Roberts decision focuses on equal protection and the 14th Amendment. Practically speaking, what that means is that voters have to be identified as being specifically injured. This is a lot like racial gerrymandering cases, an area with which the court is quite familiar. It also has the advantage that party, race, and other ways to target people can be handled by the same inquiry.

The bad news is that this involves a lot of detailed work: identifying dozens of plaintiffs, drawing alternative maps, and knowing enough precinct-level geography and voting information to evaluate partisanship and draw alternatives. These requirements tilt the playing field against reform organizations. In addition, a precinct-by-precinct approach means that remedies will usually be more limited than what a statewide measure would lead. But at least it’s a path forward.

The Kagan concurrence is nicer, statistically speaking. She points out that if political parties have the same rights as individuals, then they can be harmed, representationally speaking. This opens the way to using statewide statistics, which the Roberts decision says we have under control. It’s reminiscent of the Citizens United decision, which held that corporations have the speech rights of individuals. And who wrote that decision? None other than Associate Justice Anthony M. Kennedy, the swing vote then – and now, in partisan gerrymandering cases.

I wish the court would adopt the Kagan approach. But there’s a substantial chance that they won’t. At least Kagan has described a theory to help litigants file suit in state courts. Wherever the state constitution has a First Amendment-like clause, her concurrence could be quite useful.

In the meantime, it looks like a new need has come to the foreground: a need to evaluate partisanship using maps and individual districts. As much as I had hoped a geography-less approach would be found suitable, it looks like we’re all geographers now.

Fortunately the Princeton Gerrymandering Project is on the case. We are gathering geographic data in several key states now, and hope to cover most contentious ones over the next year or two. It’s a big job ahead, and now the Supreme Court has given us all the more reason to do it