History says that if a sitting vice president wants to succeed his retiring boss, the nomination is usually his. Think: Nixon '60, Humphrey '68, Bush '88, Gore '00. But history may not help Joe Biden in 2016.
Of the eight senators retiring in 2014, six of them are Democrats. Which should be good news for the Republicans. Maybe. Plus: take our poll, please, as to who will win in South Carolina next week.