Decrying polarization is the everyone's favorite game in Washington, but in the case of the Supreme Court, it's statistically measurable. On Monday, the high court handed down three 5-4 split decisions in its four most recent cases. Considering the outcome, and the fact that a likely five-four split will be on its way for the health care reform ruling, The New York Times Juliet Lapidos was curious if the court is more divided than it has been in history. Turns out: There's a strong case that it is. She consulted Lee Epstein of the University of Southern California and Andrew Martin of Washington University in Saint Louis for their statistics on Supreme Court rulings.
By looking at percentage of 5-4 split decisions in the last half-century of Supreme Court cases, today's court led by Chief Justice John Roberts holds the record for most closely divided court, with 22.2 percent of its decisions being 5-4, compared to 11.7 percent for the court led by Earl Warren 50 years ago. We graphed the results above. (For 1969, cases decided by 5-to-3 votes were included because there were only eight justices seated for that term.)
Now, it's worth noting that the Roberts court isn't always divided by partisan lines. As Lapidos notes, "Chief Justice Roberts wrote today’s dissenting opinion in Salazar v. Ramah Navajo Chapter. He was joined by Justices Ginsburg, Breyer, and Alito." That's quite an ideologically diverse group. Still, we know by the legal opinions of the court, that this sort of split isn't the norm. The broader question— does divisiveness matter— mostly depends on how you view the court's decisions. But certainly, for those who like to think of the rule of law as objective and ideology-blind, it's a rude awakening.