It has been reported that this term is shaping up to be one of the most liberal at the Supreme Court since 1969. Another report by Eric Posner shows that the justices appointed by Republican Presidents are agreeing less among themselves, while the justices appointed by Democratic Presidents remain a united bloc.
We should be cautious about reading this information as a trend. The case mix changes from year to year and thus there can be expected to be overall ideological variation from year to year depending on that mix and the justices’ idiosyncratic views. But there is no doubt that the country is moving left at least on social issues and the oldest adage about the Court’s decision-making is that it follows the election returns. Certainly, the expected creation of a right to same-sex marriage would be unimaginable without the rapid and dramatic shift in public opinion on the issue.
The more interesting question is why Republican justices tend to fracture while the Democrats stay united. The first reason is that Supreme Court opinions implicate not only ideology, but jurisprudential methodology and Republicans are more divided on jurisprudence.