At Supreme Court, 5-to-4 Rulings Fade — But Why?

An election year effect or something else?

A year ago at this time, the Supreme Court had decided 13 cases by votes of 5 to 4, out of 41 total decisions. That proved to be an accurate snapshot of a highly polarized term. By the time the court wrapped up its work five weeks later, a third of the cases — the highest proportion in years — had been decided by margins of a single vote.

But so far this term, with 35 cases decided with full opinions, there has been only a single 5-to-4 decision. It came in a low-visibility statutory case, not in a hot-button constitutional one. And the justices did not break along the ideological divisions that shaped the last term. Justice Anthony M. Kennedy, who was in the majority in all 24 of last term’s 5-to-4 decisions, voted in dissent.

Justice Kennedy’s dominance last term was so complete that, of 68 decisions, he cast only two dissenting votes. He has already dissented five times this term. So have Justices Samuel A. Alito Jr., Stephen G. Breyer and John Paul Stevens. In other words, no longer the essential justice, Anthony Kennedy now looks like just one of the pack.

Something is happening, clearly. The question is what.