Some people say that Justice Souter is a Yankee Republican, and that he seems like a liberal only because the GOP has shifted so far to the right. In an earlier day, the argument runs, he would have been considered a Justice on the conservative side. I confess I find this claim puzzling, and I wanted to offer some thoughts about why.
First, consider the fact that the two Justices on the current Court who vote most frequently with each other are often Justice Souter and Justice Ginsburg. Looking at the current Supreme Court Term, for example, the Souter/Ginsburg pairing is the most common: They have fully agreed with each other 88% of the time. The next closest pairings are Scalia/Roberts at 83%, Roberts/Alito at 81%, and Thomas/Scalia at 79%.
I think it is generally recognized that Justice Ginsburg is not a Yankee Republican, and that she would not have been a Republican if the GOP had not become more conservative. Everyone pretty much agrees that Justice Ginsburg is very much a Democrat and at least somewhere on the left. But if the Souter/Ginsburg pairing is the closest pairing on the Court, closer than Thomas/Scalia, then isn’t it a little strange to say that one is a liberal Democrat but the other is a Yankee Republican who only “seems” liberal?
Next, consider the cliche that it’s Justice Kennedy’s Court, and that the really big ideological cases are likely to be 5-4. That cliche has some force because in big ideological cases, Justice Souter is a safe vote for the liberal side. Souter is part of the “four” on the left side of the Court that makes Kennedy the swing vote. If there’s a case about affirmative action, abortion, gay rights, federalism, takings, the Second Amendment, or any other “hot” area, everyone simply assumes that Justice Souter is voting for the liberal side. Usually there’s no debate on this: You know where Souter is coming out, because that’s where he pretty much always comes out in the big ideological cases.
Making broad claims of ideology can be tricky business, so a few caveats are in order. Perhaps Justice Souter has policy views that are different from his legal views. Or perhaps he has traditionally Republican views on some policy issues that don’t come up in Supreme Court cases. And there are always various strains within ideologies; A moderate liberal might seem almost conservative to someone far on the left. Still, just based on his votes — which is the usual way to measure and discuss a Justice’s ideology — it seems to me that Justice Souter has voted as a reliably liberal Justice.