Supreme Court Voting Patterns

The other night my son Political Sphere had come home with data again. There had been the suggestion that the Supreme Court was basing decisions on politics. So he decided to look and see whether that was true.

This piece does not look at what the cases were about, only whether the decisions were based on voting as a political block. What is the pattern for who votes together, and can we make assumptions based on political leaning?

If you were to assume blocks, the conservatives would be Roberts, Alito, Scalia, and Thomas; the liberal block would be Ginsberg, Breyer, Sotomayor, and Kagan. Kennedy is considered the unpredictable swing vote. (I have counted a concurring vote as with the majority.) So, with 14 cases heard by this court, here is what we see.

The surprise is that there is so much agreement. Half of fourteen cases were decided with seven justices or more in agreement; four were actually consensus votes. Two cases had majorities of six. Only four were decided 5/4: two going to the conservative block, and the other two to the liberal block. All of the justices vote with the majority 2/3 of the time or more. Another surprise is that Sotomayor and Kagan are slightly more likely to agree with the conservative block than their senior colleagues Breyer and Ginsberg.

The single time Kennedy dissented from the majority, he leaned liberal. But he agreed with conservatives 71% of the time.

I don’t know how much predictive power this look gives us concerning the upcoming vote on Obamacare. We may disagree ideologically with several members of the court, but the data should at least give us reason to hope that the decisions are not merely political.