Unlike delegates, superdelegates are not bound to represent the popular vote of a region at the Democratic National Convention; they are free to support any candidate for the nomination.
Although originally coined and created to describe this type of Democratic delegate, the term has become widely used to describe these delegates in both parties, even though it is not an official term used by either party. The term arose in the 1970s.
Superdelegates are not selected on the basis of party primaries and caucuses in each state. Instead, superdelegate standing is based on the status of current or former officeholders and party officials, including all Democratic members of Congress.
In order for a candidate to win the party nomination for president, he or she must gain the majority of delegate votes. The purpose of superdelegates is for high-ranking Democrats to maintain some control over the nominating process. Superdelegates make up one-fifth of the delegates at the Democratic National Convention.