"Superdelegate" is an informal term for some of the delegates to the Democratic National Convention. Unlike most convention delegates, the superdelegates are not selected based on the primaries and caucuses. Instead, the superdelegates are seated automatically, on their status as current or former elected officeholders and party officials. They are free to support any candidate for the nomination.
The Democratic Party rules do not use the term "superdelegate". The formal designation (in Rule 9.A) is "unpledged party leader and elected official delegates". In addition to these unpledged "PLEO" delegates, the state parties choose other unpledged delegates (Rule 9.B) and pledged PLEO delegates (Rule 9.C).  The Republican Party also seats some party officials as delegates without regard to primary or caucus results, but the term "superdelegate" is most commonly applied only in the Democratic Party.
At the 2008 Democratic National Convention the superdelegates will make up approximately 20% of the delegates. The closeness of the race between Hillary Rodham Clinton and Barack Obama has focused attention on the superdelegates as they could come to be kingmakers as not seen in previous election cycles. . Such an outcome would result in the first brokered convention since 1952.
- Superdelegate Transparency Project
- "Delegate Selection Rules for the 2008 Democratic National Convention"
At the time of this writing on (February 27, 2008), this document was a summarized version based in its entirety on Wikipedia, in the entry titled (http://en.wikipedia.org/w/index.php?title=Superdelegate).