A third pending case threatened a huge defeat for public employee unions over the fees they charge for nonmembers. When the justices heard arguments in the case in December, its five conservative justices, including Scalia, seemed on track to rule that those fees violate the free-speech rights of nonmembers.
A ruling striking down the fees could severely damage the unions. Now, the justices may be evenly split, which would have the effect of preserving the union-friendly rules.
The court hasn't often had to deal with such a vacancy in modern times. Deaths of Supreme Court justices were relatively common in the 19th century, but not a single justice died in office between 1955 and 2005, according to an analysis by Marquette University. Chief Justice William H. Rehnquist was the last to die in office, in 2005; he was 81.
The last extended vacancy on the court came after Justice Abe Fortas stepped down in May 1969. President Nixon suffered defeats in his first two picks to replace Fortas, Clement Haynesworth and G. Harrold Carswell. It was not until June 1970 that the Senate confirmed Justice Harry M. Blackmun to replace Fortas. If Senate Republicans stick to their insistence on not approving a nominee this year, the current vacancy likely will last even longer.