In a recent analysis the New York Times showed that, while the media have focused on hotly debated cases in which the U.S. Supreme Court has rendered split decisions (often along ideological or partisan lines), the justices voted unanimously in 65 percent of orally argued cases this term--the highest share since 1953.  "Over the past four terms," notes the NYT, "even the members of the court least likely to agree voted together 66 percent of the time."




The record number of unanimous decisions may be explained by an effort by the justices to counter the accusation that they have become motivated by politics and partisan agendas.  Legal scholars point out that it may also be an artifact of the Court avoiding the most ideologically loaded issues this term: "The higher unanimity rate might reflect an increase in cases with low ideological stakes," said Lee Epstein, a law professor and political scientist at Washington University in St. Louis. "This term, about 36 percent involved questions of rights and liberties, compared with 57 percent in the three previous terms."  Finally, as noted by the New York Times, unanimous decisions sometimes merely indicate that the justices agreed on the bottom line (legal principle); in several cases the Court was deeply divided on the reasoning supporting decisions about legal principles, even prompting Justice Antonin Scalia to write "three furious concurrences."

In those cases in which the justices were in disagreement, the split tended to follow partisan lines, with Justice Kennedy (who sits at the Court's ideological center) being the deciding vote as he sided with either the four more liberal justices or, more often (about two thirds of the time), the four more conservative members of the Court.

Read more:
http://www.nytimes.com/interactive/2014/06/24/upshot/24up-scotus-agreement-rates.html
http://www.nytimes.com/2014/07/02/us/supreme-court-term-marked-by-unanimous-decisions.html?_r=0