superdelegate

noun

1. (US)A member of the Democratic Party who has been selected to attend the national convention to help select a nominee for president.

   “If no candidate won on the first round (something that hasn’t happened since 1952), voting would be opened up to 739 superdelegates, who are not pledged to any candidate. These superdelegates, also known as “automatically seated delegates,” include all Democratic members of Congress and Democratic governors, as well as other party leaders.”