With the prospect of an extended contest on the Democratic side, people are talking about superdelegates again.
The "superdelegates" are mainly current Democratic governors, members of Congress and officials of the Democratic National Committee who are automatic delegates by virtue of their positions. Unlike all other convention delegates, who are chosen in primaries and caucuses and pledged to candidates based on proportional allocation, the "supers" can vote for whomever they want at the convention. About 700 of the 4,763 delegates expected in Philadelphia this summer fall into this category. (We are only talking about Democrats here. The Republicans don't have superdelegates.)