Since 1960, the average age of a Supreme Court justice leaving the bench is 79 years old, Justice Scalia’s age at the time of his death. Three other justices will be 79 or older in 2017, the year in which the next President is inaugurated.
The most important issue in the next presidential election should be, and now is more likely to be, who will fill these vacancies.
Read more here – http://www.cnn.com/2016/02/13/opinions/scalia-supreme-court-future-chemerinsky/